Blitty

The Blittens are a species that appear in Mario & Luigi: Bowser's Inside Story. They are animate blocks that resemble cats. Broque, who is their owner, lost them sometime before meeting Bowser. They're trapped within enemies during battle, so Bowser must use his vacuum command to obtain them as an item.

Once Bowser gets them, he can go to Broque's shop and leave them there. He gets extra equipment for that. The reward for finding all fifteen Blittens is a new special ability for Bowser. The new ability involves Broggy. Players must slide the stylus like as if they were cleaning Broggy. Then he will rush into the enemies. However, if Bowser fails to clean Broggy properly, Broggy will tackle Bowser instead, causing damage. If the player receives an "excellent" rating on their attack, the Blittens will join in as well.

Trivia
Blitten is a combination of english "block" and "kitten" because literally, they are "block kittens."