Wiggler

Wiggler (Japanese: Hanachan) is the caterpillar-like creature in the Mario series of games. It made its first appearance in Super Mario World, where it first displayed its trademark characteristic of becoming red and enraged when jumped on by Mario, Luigi, or Yoshi. It usually has a yellow color. When it's calm, it wears a flower on its head. However, when it becomes angry its eyes become enraged, it loses its flower, and it becomes red. Later, it appeared in various other Mario titles, including Super Mario 64, Mario & Luigi: Superstar Saga, and Super Mario 64 DS. Wiggler underwent some major changes in Super Mario Sunshine where it multiplied its size tenfold and turned green.

Wigglers were seen occasionally in the animated series that spun off of the game. However, on the show, they were called "Caterpillars", and were always drawn like they had already been stomped.

Mario Kart: Double Dash!!
A green metro/bus that closely resembles Wiggler from Super Mario Sunshine, known as the Wiggler Train, appears as moving obstacle on the Mushroom Bridge and Mushroom City racing tracks.

Mario & Luigi: Superstar Saga
Wiggler appears as a boss in the Chuckola Cola chapter. Players fight him during the quest for the Chuckola Fruits.

Mario Kart DS
Wiggler appears as a boss in the unlockable seventh mission set. Players must race him on Mushroom Bridge, and each lap he gets faster. The first lap he is regular, the second lap he has steam rising from his head, and the third and final lap he is angry and red.

Mario & Luigi: Partners in Time
A "Swiggler" appears as the first boss, a Shroob variant of the Wiggler. The Swiggler regularly drinks glasses of green goo that contain vim (energy) drained from Mushroom Kingdom's Toad population. The Swiggler then extends tubes from it's hind-gut which plug into Shroob saucers flying overhead, which use the power from the goo to shoot beams of energy at Mario, Luigi, and their baby counterparts.

Mario Power Tennis
Wiggler is an unlockable character in this game. He is a defensive type, like Waluigi. For his power shot, he turns red with anger and whacks the ball with brute strength. His defense power shot allows him to fly. With his temporary wings, he flies to get the ball.