The Fire Lion is a vicious beast on a planet in the universe who debuted in The Little Guy. He ran down from a cliff after chasing Westley the watchdog and eventually Wander and Sylvia. Wander and Westley rode on Sylvia and stopped by a cliff that had a gap in it and started again. The Fire Lion jumped over them into the river where his mane blew out. He thanked them and said his fire mane blows up when he thinks of stuff that gets him all mad and just fumes. He swims away down the stream.
It's ironic that a fire lion can swim in the water.