Handfake

A Handfake is a creature shaped as a hand but made of black ooze. Its name is a pun on "handshake." They live on Star Hill and the Star Shrine in Mario & Luigi: Partners in Time. In battle, a Handfake holds signs with pictures of various enemies on them. The enemy picture on the sign determines how the Handfake will attack. These signs can be destroyed, causing the Handfake to bring a different sign into battle. The signs are all based on character artwork from Super Mario Bros., Super Mario Bros. 3 and Super Mario World.

Goomba
If a Handfake holds up a Goomba sign, it attacks by throwing the sign at the back of one of the Mario Bros. The Handfake can throw more than one Goomba sign in the same turn. The Mario Bros. must jump to avoid these attacks.

Paratroopa
When the Handfake holds a Paratroopa sign, it attacks by hitting a Mario Bro. with the sign. Before attacking, however, the Handfake twirls the Paratroopa sign a number of times. The number of twirls equals the number of times the Handfake will pull back the sign before attacking. After pulling back the appropriate number of times, the Mario Bro. must jump to avoid or counter the Handfake's attack.

Bob-omb
If the Handfake holds up a Bob-omb sign, it throws the sign high. If the sign is right side up when falling, the Bob-omb sign will fall on top of Mario. If the sign is upside-down, it will fall on Luigi. The Bob-omb sign can be deflected with a Hammer. However, after hit, the sign can fall again, possibly changing targets. Thus, the Baby Bros. may have to block the sign multiple times. If the Bob-omb sign hits a Mario Bro., the sign explodes, causing damage and possibly dizziness.

Bowser
When a Handfake holds up the Bowser sign, it can summon either a Boo or a Fly Guy carrying a cardboard flame cut-out on a string. The Boo or Fly Guy then hits one of the Mario Bros. with the "flame". The Mario brothers can jump to avoid this attack. A Boo means Mario is being attacked, a Fly Guy means Luigi is being attacked. Sometimes, they are in front of the opposite brother and switch right before attacking.

Trivia

 * Handfakes name are a pun on handshake and the fact that they hold fake pictures.
 * The Bowser picture depicts him as an adult, while in the time period Handfakes appear in, he is still a baby.