Wild West Boss Chests are items that can be obtained by defeating the Subject One boss that can appear in the Wild West. It, like other Main Hub boss chests, can drop gems, crate keys, hoverboards and a pet. Wild West Boss Chests cannot be burned at the Incinerator in the Junkyard. Chances for drops are not publicly listed.
As of v1.103.0, this item can be converted by the Main Hub Gumball Machine into Gum. The exchange rate is 1:1.