Grim Leecher

Grim Leechers are enemies from Super Mario World 2: Yoshi's Island, its remake, Yoshi's Island: Super Mario Advance 3, and Yoshi's New Island. These enemies resemble purple ghosts with skulls on their faces, and their name is a pun on "" and "".

Super Mario World 2: Yoshi's Island / Yoshi's Island: Super Mario Advance 3
In Super Mario World 2: Yoshi's Island, Grim Leechers are found in extra and secret levels, appearing only in The Impossible? Maze in the original game as well as Mystery of the Castle? in the remake. They wait until Yoshi comes near and then hover towards them; if a Grim Leecher makes contact, they knock Baby Mario off Yoshi's back and hop on. This causes the game controls to reverse, signified by Yoshi turning a flashing pink color. Yoshi must Ground Pound to knock a Grim Leecher loose, and can eat them to produce an egg.

Yoshi's New Island
In Yoshi's New Island, Grim Leechers appear in the fourth level of World 2, Beware the Boo Brigade. They can no longer be eaten, and the Grim Leecher-controlled Yoshi is now colored purple.

Super Smash Bros. Ultimate
A Grim Leecher makes an appearance in Super Smash Bros. Ultimate as a spirit.

Super Mario World 2: Yoshi's Island

 * Shogakukan guide: 取りつかれると、方向感覚が狂って、思うように動けなくなる. (When possessed, you lose your sense of direction and cannot move as you would like.)
 * Player's Guide: This usuper kicks Mario off, hops on Yoshi's back and reverses your controls.

Yoshi's Island: Super Mario Advance 3

 * Shogakukan guide: ふれるとヨッシー背中にとりつき、ヨッシーの操作を左右逆にしてしまう. 赤ちゃんを取りもどせば、すぐに回復する. (When touched, it attaches itself to Yoshi's back and reverses Yoshi's movements from left to right. If the baby is retrieved, Yoshi will recover quickly.)

Yoshi's New Island

 * Shogakukan guide: 接触してとりつかれるとダメージを受け、スライドパッドの入力方向が左右逆になる. 非常にやっかいな敵なので、早めにタマゴを投げつけて倒そう. (If it comes into contact with and possesses you, you will take damage, and the slide pad input direction will be reversed. Since this is a very troublesome enemy, be sure to defeat it by throwing eggs at it as soon as possible.)