From the Super Mario Wiki
Gilbert the Gooey is the main boss of World 1 of Yoshi's Island DS. He is a regular Gooey Goon that Kamek enlarges with his magic; twenty colorful spheres surround his body. To defeat him, Yoshi must eat or throw eggs at all of them. Gilbert's only attacks are swinging from side to side and moving up and down quickly.
He can be defeated easily with Baby Donkey Kong when replaying the stage, due to the power of the explosions that result from thrown eggs while carrying him.
Names in other languages
||Gilbert le Gluant
||"Glockenpocke" is a compound of the words "Glocke" ("bell") and "Pocke" ("pock")