I use my 170 basilosaurus to kill the alpha mosasaurus (level 50+) mine has 30k health. I bite until half health, rise all the way to the surface and continue until the mosa is dead. Health rises so fast at the surface!
Can kill squid like their kin in real life. Tame a 150 and you can take on alphas like they are regular ones. Just up health and memes. They recover steam so quick boosting it is pointless. An all around amazing creature, 10/10.