Smeech

Smeeches are pig-like enemies first appearing in the game Super Mario Galaxy 2. They appear as pink winged creatures with two beady eyes and plump lips.

Super Mario Galaxy 2
Debuting in Super Mario Galaxy 2, Smeeches' only method of attack is kissing and sucking Yoshi's lips and making him unable to use his tongue. If Yoshi tries to eat one, the creature will suck on his lips. They can only be defeated with a Spin or get jumped on. Also, they will run away from Mario or Luigi, unless one of them is not on Yoshi. To get a Smeech out of Yoshi's mouth, Yoshi himself has to spin his head to make it fly away, causing the Smeech to vanish, dropping Star Bits.

Smeeches are first encountered in the Yoshi Star Galaxy, ever since the first mission, Saddle Up with Yoshi. They are encountered later on in the Hightail Falls Galaxy, the Haunty Halls Galaxy, the Sweet Mystery Galaxy, and the Starshine Beach Galaxy.

Trivia

 * Smeech is a portmanteau of the words "smooch" and "leech".
 * They bear a striking resemblance to the Poink enemies from Bianco Hills in Super Mario Sunshine, in both their appearance and their method of attack, as these creatures would attach themselves to F.L.U.D.D.'s nozzle in the same way as Smeeches attached themselves to Yoshi's mouth.
 * If Yoshi goes up to a Smeech and another one is already on his lips, the Smeech won't take any notice of him and keep hovering around like normal, making an easy target to be stomped on.