Wendy O. Koopa

Wendy O. Koopa, who is named after the late Wendy O. Williams, lead singer for the Plasmatics, first appeared in  Super Mario Bros. 3 as one of  Bowser's  Koopalings. She later appeared again in Super Mario World as the boss of world 6, Chocolate Island, where she hid in pipes with two reflecting fireballs as her protection. She is also  Bowser's only daughter. She later appeared again in Mario is Missing!, Yoshi's Safari, Hotel Mario, Mario and Luigi: Superstar Saga, and now New Super Mario Bros. Wii.

Hacking Information
All the Koopalings are contained in Sprite 29. To use Wendy, you must set the sprite to X=12, Y=6 (making her the bottom-most option, as the sprite can be used with Y equal to anything from 0 to 6). You must also use the Wendy/Lemmy tileset or set SP3 to GFX0A. (Why this tileset sets SP4 to GFX22 is unknown.)

Unlike most bosses, the boss room that Wendy is in (D3, as well as unused rooms at 94 and 193) can be edited with Lunar Magic. Lemmy's boss room (1F2, unused 93 and 194) is the only other boss level that can be edited like Wendy's. She is immune to Koopa shells, though the decoys are not. Note that hitting the decoys with a shell will cause them to launch off to the side of the player's screen, warp to the other side, fall down, warp to the top of the player's screen, then finally disappear.

Boss Battle
In the battle, Wendy herself does not attack, instead popping out of one of the pipes in the arena at random. The danger comes from the Reflecting Podoboo bouncing around, which has a habit of blocking you off from Wendy. Along with Wendy, two decoys appear in other pipes. Attacking them gives points, but does not deal damage to Wendy. In essence, the battle is reaching Wendy and stomping on her head before she dives back into her pipe, while also avoiding the Podoboo. Defeating Wendy plunges her into the lava below.