Torpedo Ted

Torpedo Teds are torpedoes that move underwater. Torpedo Teds are relatives of the much more common Bullet Bills, but the torpedoes are larger than their bullet brethren. The torpedoes are dropped by Skull Boxes, just as Bullet Bills are fired from Bill Blasters.

Super Mario World
Torpedo Teds first appeared in Super Mario World and resided in Soda Lake. Mario and Yoshi encountered Torpedo Teds during their adventures in Dinosaur Land. Torpedo Teds moved fairly fast and could be hard to avoid due to the narrow pathways within Soda Lake. These torpedo enemies are also indestructible.

Super Mario Galaxy
Additionally, Torpedo Teds appear in Super Mario Galaxy. They only appear in Buoy Base Galaxy and Drip Drop Galaxy. Torpedo Teds resemble and act like the Bullet Bills featured in this game. As such, they would home in on Mario then explode, just like a Bullet Bill. However, these Torpedo Teds make a beeping noise based on how close they are to Mario, unlike Bullet Bills. Torpedo Teds are also fired from cannons that resemble underwater Bill Blasters. In this game, these torpedo enemies could only be defeated by Rainbow Mario, or by causing them to crash into a wall, each other, or some other object. In Buoy Base Galaxy, Mario (or Luigi) have to make the Torpedo Teds follow them and crash into wall. So, they can complete the level. In Drip Drop Galaxy, they are just useless enemies chasing the player around.

New Super Mario Bros. U
Torpedo Teds reappear in New Super Mario Bros. U alongside Skull Boxes. In this game, they are similar to those in Super Mario World in both appearance and behaving. A red version of Skull Boxes appearing in the game launch red missile Torpedo Teds, known as Missile Torpedo Teds, which chase Mario in a way similar to a Fishbone or Missile Bill.

Super Mario World television series
A Torpedo Ted, though not specifically named as such, appeared in the final episode of the Super Mario World cartoon. In the episode, titled "Mama Luigi," Luigi and Yoshi, after narrowly escaping a pursuing Rip Van Fish, were attacked by a Torpedo Ted. This Torpedo Ted chased after Luigi and Yoshi as the two swam to the surface; however, the torpedo missed both its targets as the duo was saved by two friendly Dolphins.

Super Princess Peach
Torpedo Teds also reside in a few underwater areas of Vibe Island as depicted in Super Princess Peach. Many are under the influence of the Vibe Scepter, transforming the torpedoes into Glad Torpedo Teds.

Trivia

 * Torpedo Ted's name, along with Bullet Bill's, is a reference to the movie Bill & Ted's Excellent Adventure.