The Monkey Ace Bloon is a Bloon in Bloons 2 and Bloons 2 Christmas Pack. It is represented by a blue color with a target symbol on it. Popping it will give the player a set of two flags. With the flags, the player can move the mouse in any direction; then the player can click to summon a Monkey Ace that will pop bloons in a straight line. It will explode (doing no bloon damage) when it hits frozen bloons or blocks as well as dropping the pilot Monkey with a parachute.
This Monkey Ace is completely different compared to the Bloons TD Ace, in that it does not fire darts. Instead, it cuts up Bloons with its propeller.