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 are near harmless lumps of seaweed. The only way to tell is they're normal seaweed or Whirlweeds is the same as the Minjos, just shoot eggs at them from a distance. They can be destroyed with most attacks with one try which make them a weak enemy.