Moldworm
Quote from The Legend of Zelda: The Minish Cap Moldworm figurine:
"Appears in Minish roads. They come out of the ground when they sense prey. If you get swallowed, you’ll take damage and get all dirty!"
Moldworms seem to hold a symbollic relationship with Pestos because when Link gets all dirty by being eaten, any Pestos in the area are attrated towards Link more quickly and attacked more often as compared to when he is clean.