The Blitties are a species that appear in Mario and Luigi: Bowser's Inside Story. They are animate blocks that resemble cats. Broque, after meeting with Bowser in Dimble Wood requests that Bowser locates and bring him these "rare creatures". 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 Blitties 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 Blitties will join in as well.