Otters likes shalow lakes and watterfalls. Best way to tame otter is to kill all salmons around it, cause corpses has long time before it disappears and straight away feed them without any intervals cause they dont have cooldown on feeding time. After tame pick it up and you will get insulation from cold. Leveling otter is best to give all stats to oxygen as it increase insulation resistance. And you will forget biome struggle :) good luck finding them.
On Aberration having trouble taming otters? Use a crab pick it up dip claw in water now otter is high enough to tame. No more dead fish blocking feeding prompt. Still tricky but faster by far. Tilting crab on rock or slight grade on side of river helps to dip claw, deeper pools also.
These little guys are so much easier to tame in mobile, but harder to find. You still need to kill a megipirahna, but you don’t need to grab its corpse to feed the otter. After harvesting its meat you can easily walk up to it and feed it until it’s tamed. It doesn’t run away in mobile, and I’m sure you can use any fish meat.
best to tame a ichthyornis and carry it with you when looking for one of these guys, put the ichthyornis on hunt and retrieve it will catch a fish and bring it back golden and will have a better taming affect to feed to otter, like this up its very important peeps must know :)))