Aku Aku is a magical mask that protects Crash Bandicoot and serves as a useful ally to him in most Crash Bandicoot games. Initially appearing simply as a power up, in the third game he gained a voice and personality. That game also introduced his twin brother Uka Uka who the complete opposite of him and naturally teams up with Dr Neo Cortex. In the Crash Bandicoot games, Aku Aku can be found in crates with a picture of the a mask on them. Once the crate is smashed, Aku Aku will be released and will allow Crash to be able to withstand one hit from an enemy. Break another crate while you already have Aku Aku protecting Crash and you will be immune to two hits from enemies. However, break three crates without losing a mask and Crash will be granted temporary invincibilty.