On Mystery Island, look behind Cortex to find an owl-shaped lamp. Use the body-slam switch to raise the lamp, then enter the revealed cave and run to the right. Talk to the Drone at the top of the small island and buy the costume for 2,000 Coins.
Crash's Skeleton Costume
Talk to the Astro Land worker near the stunt arena and buy the costume for 4,000 Coins.
Easy coins
Drink a Whumpa Whip and let a Ninja Penguin attack you. Then, pick up your coins.
Japanese Crash
Press B, X, B, X at the main menu.
Play as Crunch Bandicoot
Give Cruch Bandicoot 2,500 Coins at Midway.
Play as N. Gin
Give N. Gin the Green Plutonium at Midway.
Play as Nina Cortex
Giver Nina Cortex the keys at Midway.
Play as Pasadena Opossum
Give Pasadena Opossum one Power Crystal at Midway.
Play as Von Clutch
Give Von Clutch one Power Crystal at Midway.
Third Tier Kart Weapons
Spend one Power Crystal at Midway to buy the following character's third tier kart weapon from them: Coco, Crash, Crunch, N. Cortex, N. Gin, Nina, Pasadena, and Von Clutch.