You can kinda break the game and take them with a fish basket. The dont use any food and they cant level but hey, you have one now

GUYS WATCH YOUR BUTTS, THEY ARE MORE DANGEROUS THAN A GIGA, RIGHT UP THERE WITH DODOS

Ah the Trilobite... Also Known as the Cockroach of the Sea!

If you so much call these creatures an idiot, their giant crab cousin will fly from his home in Aberration and throw you 500 feet in the air.

Dododex is wrong once more, they are tameable it just requires a very special item enable to tame one: forcetame.