There is scene in which a lizard is taking a bath, and something that looks like it could be his penis is visible. Whether this is a goof, an intentional subliminal message, or just another part of his body is unclear.

There are several scenes involving animal mating rituals and mating behavior.

There are several scenes showing animals fighting and animals killing and eating each other.

many frightening animals are depicted throughout the series, particuarly in the episode "Scary Animals".