The Lion Fish is an orange and yellow creature. It looks a lot like a Sea Bear and a Sea Rhinoceros. It is a fish with a head and claws of a lion and a body of a fish. It is a captive in the Chum Coliseum by Plankton, in the episode "Spongicus". It chased Patrick for having a bunch of sausages around his neck (it's the lion fish's favorite food). SpongeBob takes the sausages around Patrick's neck and throws it to the lion fish, which hit Plankton. This caused the lion fish to chase Plankton. It is later seen at The Krusty Krab, working as a "financial expert" of Mr. Krabs, which he uses to scare customers into buying Krabby Patties, now for 10 dollars.
The creature does not resemble to its supposed namesake, and is very much like an African male lion and a Goldfish.