The Vault Boy (Vaultボーイ, Vault Boy) is the mascot of the Fallout franchise.
The Vault Boy is the mascot of the company Vault-Tec from the Fallout franchise by Bethesda. Vault-Tec designed post-apocalyptic shelters called Vaults to enable humanity to survive in the aftermath of a worldwide nuclear war, though the majority of these Vaults were in reality controlled, often unethical human experiments. The Vault Boy illustrates character statistics and selectable attributes, and from Fallout 3 onward, models wearable equipment. Vault Boy should not be confused with the Pip Boy; the wearable computer used by the player to access their inventory.
As a costume
A DLC costume for Mii Gunner based on the Vault Boy was announced on June 22nd, 2020, and was made available for purchase on June 29th, 2020. Like Sans and Cuphead before him, Vault Boy appears as a fully modelled character. His "mask" is just his head instead of a mask with the Mii's head visible. His gun appears to be based off the Alien Blaster, an energy pistol that shows up multiple times throughout the series. His Vault Suit is labeled '111' on the back, a reference to the Sole Survivor's vault in Fallout 4. Unlike Sans and Cuphead, Vault Boy does not come with a music track due to most of the music in the Fallout series being licensed music.
In his reveal trailer, the opening features Mario performing his thumbs-up taunt. This is a reference to a thumbs-up being Vault Boy's signature pose. Later, Vault Boy fights Dark Samus, referencing various mutant enemies seen in the Fallout series, Finally, Vault Boy stands besides Duck Hunt. This is a reference to Dogmeat, a recurring dog companion throughout the Fallout series.