In the Adventure Time episode (Season 10, Episode 2), BMO and Ice King team up as eccentric door-to-door salesmen. While it starts as a whimsical adventure, it becomes a pivotal plot point that alerts Princess Bubblegum to the return of a major threat. Plot Summary
: BMO and Ice King (dressed in a "totem pole trench" coat) begin selling random items, such as lint and branches. After a successful sale to Tree Trunks, they get lost while chasing a chipmunk. [S10E2] Always BMO Closing
: Revealed as a major antagonist, he is one of Princess Bubblegum's early candy creations who seeks to usurp her. In the Adventure Time episode (Season 10, Episode
: They stumble upon a ziggurat inhabited by a mysterious figure known as "Uncle G" (Uncle Gumbald). [S10E2] Always BMO Closing