Whirlweed

Whirlweeds are located in the Seaweed Sanctum in Jolly Roger's Lagoon (Atlantis). They hide themselves as a lump of seaweed, but attack you whenever you get close enough. They usually camouflage themselves near harmless lumps of seaweed, making it difficult to determine whether a given lump of seaweed is really a Whirlweed or not. However, shooting it with eggs is an easy way to determine whether or not it is a Whirlweed; if it takes damage, it is a Whirlweed, and if it does not, it is a regular lump of seaweed. They can be destroyed with most attacks with one try.