<P> Crash Bandicoot is a series of platform video games created by Andy Gavin and Jason Rubin . The game was currently published by Activision . The series was formerly developed by Naughty Dog from 1996 to 1999, and by Traveller's Tales, Eurocom and Vicarious Visions from 2000 to 2004 . The series features a large cast of distinctive characters designed by numerous different artists, which include Charles Zembillas and Joe Pearson . It also features a cast of veteran voice actors . </P> <P> The series centers on the conflicts between a mutated bandicoot named Crash Bandicoot and his creator, Doctor Neo Cortex . Crash acts as the main playable character of the series, though other characters have had occasional player access, such as Coco Bandicoot and Doctor Neo Cortex, as well as Crunch Bandicoot . </P> <P> Aku Aku is the guardian of the Wumpa Islands and the father figure of Crash Bandicoot and his friends . Aku Aku is the spirit of an ancient witch doctor encased in a floating, wooden mask . During Crash's missions to stop Doctor Cortex, he scattered copies of himself throughout the travels in an effort to aid him in his mission . Whenever Crash possesses an Aku Aku mask, he will be shielded from one enemy attack or contact . Collecting three Aku Aku masks gives Crash temporary invulnerability from all minor dangers, but does not protect from falling down holes . In his English speaking appearances, he was voiced by Mel Winkler up to Crash Twinsanity, excluding Crash Bash where he is voiced by Sherman Howard, and Greg Eagles from Crash of the Titans onwards . </P> <P> In the first game and Crash Bandicoot 2: Cortex Strikes Back, he is a background character that helps Crash . In Crash Bandicoot 3: Warped, his evil twin brother Uka Uka is introduced when the ruins of Cortex's space station crash into Earth and set Uka Uka free so Aku Aku tells Crash and Coco Bandicoot the story of how he locked Uka Uka up in an underground prison many eons ago . He then gives the two the assignment of gathering Crystals that lay scattered throughout time and keep them from the hands of Uka Uka and Doctor Cortex . During Crash's final fight against Doctor Neo Cortex, Aku Aku fends off Uka Uka's attacks while the fight is in session . Aku Aku appears in Crash Team Racing as a tutor for Crash, Coco, Polar and Pura, giving them useful tips and tricks throughout the game . He also appears as a power - up during the races, protecting the said characters from all attacks and obstacles while giving them a speed boost . However, he cannot protect the characters from chasms and deep water . In Crash Bash, in order to resolve his constant fighting with Uka Uka, Aku Aku summons Crash and Coco as part of a contest between his players against Uka Uka, Aku Aku is later allowed to have Tiny and Dingodile into his team as to even out the number of players between them . During the course of the tournament, Aku Aku begins to suspect that Uka Uka is using the tournament to disguise a secret plot of his own . He discovers this plot to steal Crystals just in time for his team to win . Aku Aku locks the Crystals up into a secret cabinet for safekeeping, and banishes Uka Uka into the vacuum of space as punishment for trying to abuse the power of the Crystals . </P>

What are the masks called in crash bandicoot