Salvo the Slime

Salvo the Slime is the boss of World 1 in the game Super Mario World 2: Yoshi's Island. Salvo is a Slime that was transformed into a Slime by Kamek. Salvo jumps at the player, trying to push them into a lava pit below his arena, though unlike most enemies, the player is not hurt by Salvo's touch. Instead, the Yoshi is hurt by the Lemon Drops that Salvo summons. Unlike most Slimes, Salvo cannot disguise himself as a box. Because Salvo was a Lemon Drop prior to his transformation, Lemon Drops break off of Salvo when he is hit by an egg. The more Salvo is hit, the smaller he gets, until he disappears altogether.

Salvo the Slime also makes two appearances in Tap-Tap the Red Nose's fort. After the player defeats Salvo in Tap-Tap the Red Nose's fort, they will get a key. Unlike the prior boss fight, Salvo in this instance can disguise himself as a box.

Salvo makes an unexpected appearance as the boss of the second floor of the Duel Tower in Mario Party Advance. This game shows that he is capable of speech. Salvo then challenges the player to a game of Volleybomb, and, once he loses, the reward is the mini-game.

He also makes a brief cameo alongside other Super Mario World 2 bosses in the opening to Yoshi's Island DS.

Trivia

 * Although Salvo is indeed a name (actually a surname), its use in this character's name is likely a pun on "saliva," referencing his slimy texture.