Hi everyone !
First thing : I'm french so if I make any mistake, just tell me ! : ]
As I'm used to make quite long posts - and any which pretends to 'guide' should be - I've made silly paragraph titles in orange ! It'll be more convenient to read.
Update:
Spider & Gel (& Troll) tests added. Fire & Poison ones reworked, the latter seems to be the best.
Science vs Reports
I don't think this post could serve as any scientific weighed-up decision, because it states my opinions I tried to make the most objective possible and it's no matter about numbers. Still I hope to give hints to people interested but "lost" in Fishing ..!
Also, doubtful or not, I'm very willing about hearing any of your tests or findings !
(All tests have been made with Torchlight v1.15, with a l.80~ character (Devastate Destroyer), on various creatures from the Lizardmen's Caverns, and mainly themselves. Pet Mastery at 10.
I did not make any timed tests cause too many elements are playing a part. For this we would require a testing area with idle monsters and such.)
"Mods", no thanks
Please don't make replies to offer an umpteenth "mod" which could fix a "problem" in your view ; I'm here to talk about core Torchlight, the one which has been designed, conceived, chosen by Runic Games. The current balance is as it is for a reason and I'm dealing with that.
If you deny it, that's not Torchlight, but YOUR Torchlight ; and as I don't disrespect any of that kind of choices, that's about things I disregard completely - in order to make an objective and common guide for anyone..!
...So, here you are, you love your pet, you're so fond of a deserved fishing time after a bloody mess and lucky drops... You throw your fishing rod, things bite the hook, you make incredible loads of icky spastic fishes... But you don't know anything about what's better to keep and your backpack is never larger enough !
Tonight having my bag fulfilled with things I've become used to not use, I've done some tests with those cuties :3
Stats
On this page you can see a list of all known fishes and their different sizes, and the stats effects on your pet. For more convenience I quote it here :

Notes about this table :
- The Improbable Large Fish, transforming your pet as a Troll for 30s only, is not listed here.
- The Thorned Strider and the Tattered Lurker notes are false, tested with Heal All and I encountered no problems.
- Did not see any Charm ability from a Mimic.
As you can see with stats, only few seem to be good. But what about attack speed, potential AoE skills and such..? We'll see things aren't that obvious !
Zero HP = flee
I'd like to make one statement before giving my results :
As I did let the pet only fight, I noticed that even nearly zero health it continued to fight. Only at zero it was fleeing, gaining then some life and it wasn't anymore. I don't know if that's any bug or glitch, one time it fled while going under a threshold of like 1/10 life left, as I used to know in the 1.00 version of Torchlight. I don't know what to think here. As the pet's main behaviour for 30h experience was to continue fighting and rarely flee, I'll consider so in my conclusions.
What does this mean firstly, well that Defense & HP stats will have not much importance, with you on the scene ; except perhaps in the aggressive mode activated (useful in HC apparently ?..), as the pet will be alone and surrounded :'( and if not fleeing it'll mostly be taking hits rather than make successful attacks.
Pretence
Given the Attack stat, only Varkolyns (1.4), Mimics and Elementals (1.25) seem worthy.
Given Defense/HP stats, only Burrowers (3.75HP) and Mimics (2.5HP) seem so ; there's no transformation which boost Defense, much valuable than HP.
You understand that any transformation reducing it is rejected.
In an overall view, Mimics, Burrowers, Varkolyns and perhaps, Elementals seem to make it. Goblinhounds are quite equal.
Well...
Analysis
Monster skills & Notation
See any monster skill here. I've put the info next to their name anyway.
Some transformations are even worse than the original form of the pet. I put a ' ! ' before its name ; the really best ones are with a ' + '.
When I quote skills it's matter of DPS, but saying that 100% DPS = a normal attack is apparently true. From my observations I use the term "damage" though.
GO!
Let's start !.. (at last!!)
...with the Varkolyn, the best Attack owner (1.4). Actually it's very stupid, it'll either take its time or run around with no reason, like fleeing for pleasure. :l The Jump Attack (100% DPS / 3s Cooldown) is rather fun but happens not very often. The Varkolyn is very confused and DO more damage, but its attack speed, lack of skills and global behaviour make it very mediocre. Too bad for such a look.
Then the Mimic ! (Rare fish) Here's a great deal for sure ! Well in my experience it's rather common. Quite fun to see, wacky style, it seems to me that it endured a slow hit recovery speed though. Normal attack speed, it's not BAD, it's good, while not being mighty and impressive. Only HtH contact but it's not boring. Choose it for its cuteness ! <3
Note : This Charm ability has not showed, if any of you can tell if the Mimic is able to cast it...
Okay, next the Goblinhound to make it done. I believe with 0.8 Defense but 1.9 HP, and Heal spells, this should balance. So it's more a matter of taste again, too bad it don't Dash (110% DPS, 15 Knockback) more often, doesn't seem to trigger in any HtH fight like Lizardmen or Disciples, but to use a minimum range. Normal attack speed I believe, quite squat looking, it's like an evil version of your dog :] When you got nothing else, it could be fun.
What about a !Thorned Strider ? (Rarer fish.) With such stats, we count on its abilities, which are... None. It's less tall than its monster replicas, but still "scary". Attack speed, hm I'd say normal though it seemed to be hesitant to strike, but chances are that's my imagination. Well, always that same Heavy hand hit, really no efficiency nor fun over here. :C Why this fish costs more..?
Time for the !Tattered Lurker (Rarer fish.) to show if those poor stats are for a bigfatdeadlyskillfromthesky. Well, NO. It's even faster but still makes less damage. Really too bad cause that's the only winged transformation the game offers (which in my humble opinion are in fewer numbers anyway |< ). A bit more little than monster replicas. Try it, and forget it. But why this one costs more too ..??
Well the !!Spider is even worth trying. Worst stats, no skills, well I even didn't see that poison bolt but really, uhm, same that above, faster attack speed, and weeaaaaker. It's just weak. Oh well. Spiders are disgusting.
So much bad news indeed.
So swap this sh*t with for the Gel. There's a difference. Its basic Shock electrical AoE attack is bad, but sometimes it casts ShockMode (100% cast Gel Shock when hit - which is 200%DPS) and this one is brilliant. Harsh for one second. But it needs to get hit, and it's not that often, else shy blobby attacks. Well it's so special looking and making such weird sounds that it's a "fun" companion ; don't expect that it'll make you have less hassle.
Would the Burrower bring us at last awesomeness ? Not bad. But oh god what a shitload of HP for real yo. And it bites ! So cool. Normal attack speed. Sometimes, it makes a AoE electrical attack, Shock (50% DPS, Cooldown 6s) and as you see it's weak :l But okay. Very funny to see, the Burrower actually classy looking and the HP huge boost make it neat.
Note: I can't see any Elemental monster skill on TLArmory, if you have any hints...)
You surely noticed the +Fire Elemental. It often casts a good Lava AoE with damage over time (I'd say x0.4 damage every second, not so sure), and with his three Fireball shots (x2 damage each..?), in close contact it's really dealing heavy harm. Every Elemental have a clap HtH attack which is very equal. The main thing is its sustained speed. Yeah this one a definitely a great choice.
Then comes the mighty +Poison Elemental. The Poison nova it regularly casts is enormous in a close fight, hitting nearly every monster anyway (x2 damage or less per bolt - when this shit crits, srsly it's mindfuck). Its three Poison balls (different from Zealot's Ember bolt) are fine (x1.5 or less) but a little slow. Again as they're homing, in contact that's all one shot and it f*hurts. Its cast speed makes it so aggressive. I did not noticed any particular poison damage over time, strangely. The Fire Elemental is doing well with loads of foes, the Poison one has no AoE but still large range, and will do a strong wipe on contact with an unseen amount of damage. Nothing less, enough said.
Next, the !Electric Elemental should be kickass ! Not at all :l I don't really understand, its lightning attacks are weak and it clearly seems to be hesitant on striking - or is the attack (cast) speed under its congeners..? Also I noticed some presumed AoE attacks such as a lightning coming from sky often don't deal anything, like no damage as if monsters dodged it while being very close to it - on this point I'd really appreciate feedback. The weak skills of this one just surprised me but that's it, WEAK :l
Last but not least, the Ice Elemental isn't bad though its sky Ice meteor seem also to simply miss targets sometimes (else x2 damage or even more), its fair three ice bolt (x1 or a bit more ..?) is a good support ; same thing here, its speed is above normal. Plus it slows foes, not as badly Frost VI can do, but still the half I'd say. Steady choice, pretty classy and handful.
The very last one... the Troll. Well. It's hard to tell. You're able to see that wide heap of muscles for only 30s, and it's very fast, because this Troll is very slow. Either moving or attacking with only is huge fist repeatedly, it's just too SLOW. Since its stats are quite the best [HP: x3,1 / Damage: x2~ / Defense: x1], and numbers displayed outstanding, it really didn't amazed me in any point, so I'd be glad seeing someone contradict me ..! For that amount of time, I hope I should be wrong.
Relativity
So all these observations are here to show what is efficient. And efficient within the pet possibilities, because when a Poison Elemental needs 10s or so to liquefy a Lizardman, with a Devastate Destroyer I make two. So that's utterly the reason why make one's choice considering personal tastes.
In order to choose an appropriate Giant fish, note that "permanent" transformation means "permanent until another fish fed" !
But still I encourage everybody to make any choice about looking, appearance and personal rating ! (Exactly what we don't need and should disregard on those - and any - tests & observations..!)
Equipment
I made a little research about what equipment could assist us on Torchlight Armory with our glorious fishy quest :3
I found no shields, and only few weapons.
Helmet : Sushi Helm >> 20% Note: Really easy to have, check the recipe !
Rings : Motar's Band >> 5%
--> Tanwanteng's Bad Influence >> 10%
Necklace : Fisherman's Friend >> 10%
Boots : Valcone's Butt Kickers >> 10%
One 1H Mace : Chainfist >> 5%
And one Pistol : The Drunkendwarf Persuader >> 1%
--> 2Handed Polearm : Eleven Ton Hammer >> 10%
Belts : Shadow Sash >> 1%
Gloves : Transmuter Gloves / Dragonscale gauntlets >> 1%
Chest : Nargothrel's Vest / Dragonscale Chest / Zoromun's Ideal / Zoromun's Ideal >> 1%
Shoulders : Transmuter Mantle >> 1%
Fish : Emberbright Cod >> 50% for 1200s aka 20mn
You can also eat this rare fish to fish more... fish. Great. I love that.
(Dunno if it stacks, I've read a test stating eating one was a big difference, two wasn't.)
So without the sweet latter we can have a maximum global permanent bonus to Fishing Luck of 64%. So 114% with the Emberbright Cod. Weeeeee.
I'd be quite interested to see what differences happen. Actually.
Yummy
What about those consumables, Glowing Shark for +1 permanent Magic (what about other stats??), Albino Halbut for +10% block /5mn, Ember Fish Eye for +20% Exp gain /5mn, classic Bearded Fish for +25% armor /5mn (which happen to be much higher, with my poor 10x Def my armor is doubled...), or this Ordraak Polyp for +25%Magic Find for 1 hour ..?? And other pet buffs...
...Or even those mysterious socketable Lucky Fish Tooth (+3 crits) or Devil Fish Eye (+5% Attack speed) ..?! I say yum. YUM.
Areas
Last chapter and short one.
Still from the wiki page, we can point out that the Black Palace can nearly drop it all, but not so sure it's the best choice.
The Crypt seem more appropriate to drop Firefish, Venomfish, Ice Angel & Pocketfish (and badly Birdfish, Bog Perch & Electrical Eel) ;
the Estherian Ruins bring up Gold fish, Improbable large Fish & Pocketfish (Birdfish & Electrical Eel for the worst).
Anything like Web fish, Glooper Jelly, Bat fish, Muckfish & Tunnel Shark is not stated, but is available.
I wonder if those statements are valid for the Shadow Vault... Perhaps they exactly are, and those in the Main dungeon cut off best ones (until the Black Palace). Reports are needed !..
...Aaaannd done ! That wasn't that boring, was it
Here's the ending of my Guide for Pet transformations ! Hope that'll help you to discern what suits you, and remember, your taste above everything !
Also please don't hesitate to give any feedback on this. Either your doubt or your enthusiasm could be useful to confirm facts or dismantle beliefs !
Greetings Torchlight (FISH) lovers & Endless Respect to Runic Games ! Live long !
Much fishy love,
T.


