I usually call Larry and Kolt a Squid and a Dragon but it's appropriate to call them a Monster and an Alien as well since one is basically a weird cryptid species of squid that calls itself "Krakens" sometimes and the other is a reptile from space that calls itself a "dragon".

in the latter case because it's easier to explain than some weird xenobiology diatribe, and in the former because "Larry the Prairie Squid" doesn't sound as cool as "Larry the Kraken."