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. In his English speaking appearances, he is voiced by Mel Winkler up to Crash Twinsanity, and Greg Eagles in Crash of the Titans and Crash: Mind over Mutant. In the Japanese versions of his speaking appearances, he is voiced by Kenichi Ogata up to Crash Twinsanity.

Crash Bandicoot, or simply Crash, is a title character and the main protagonist of the Crash Bandicoot series. Introduced in the 1996 video game Crash Bandicoot, Crash is an Eastern Barred Bandicoot that was genetically enhanced by the series' main antagonist Doctor Neo Cortex and was soon banished from Cortex's castle for his perceived unworthiness. Throughout the series, Crash acts as the opposition against Cortex and his schemes for world domination. While Crash has a number of offensive maneuvers at his disposal, his most distinctive technique is one in which he spins like a tornado at high speeds and knocks away anything that he strikes.

Doctor Neo Periwinkle Cortex (often referred to as Doctor Cortex, or simply Cortex) is a video game character and a main character of the Crash Bandicoot series. His name is a play on the term neocortex, an area of the brain. In the series, Cortex is depicted as a mad scientist who seeks to achieve world domination as an act of vengeance for the ridicule he has suffered in the past. Hoping to achieve this by mutating the local animals into his soldiers, he eventually creates Crash Bandicoot, the titular character of the series, but soon rejects him as unworthy of being in his army and removes him from his castle. As Cortex's actions endanger the sanctity of the islands the games are set in, Cortex's plans for world domination are often hampered by Crash along with other characters. Crash's constant interference has made eliminating Crash one of Cortex's top priorities along with world domination.

Doctor Nitrus Brio is a scientist who formerly worked under Doctor Neo Cortex. Brio was created by Naughty Dog as a foil for Doctor Cortex: "meek to Cortex's strength, logical to Cortex's emotional, successful (his inventions work) to Cortex's failure." Brio is voiced by Brendan O'Brien in the English versions of Crash Bandicoot, Crash Bandicoot 2: Cortex Strikes Back and Crash Bash, and by Maurice LaMarche in Crash: Mind over Mutant. He is voiced by Mitsuru Ogata in the Japanese version of the series up to Crash Bash. His name is often abbreviated to "N. Brio", a wordplay on "embryo".