Gooey

Gooey is the name of an enemy resembling a Boo from Wario: Master of Disguise. They appear as common enemies in Blowhole Castle. The top part of its head goes up and down, separated from its body. The Gooey attacks by sending a lot of smaller Gooeys at Wario. They hit Wario and take away his hearts. The only ways to get rid of them is to hit them with the stylus or just leave the room. Also, Gooeys do not attack when they are invisible and cannot be seen by Wario. To defeat the larger Gooeys, the player has to shoot them while being Cosmic Wario. The player can also hit them with Poop while being Arty Wario, or some other attack. They are No. 4 in the enemy glossary.

In-game description
''This kind ghost tries to appear wherever folks expect to see a spooky spirit. Haunted mansion? Abandoned slaughterhouse? He's your man.''