In How It Began, Rake suggested to Horn and Pipey that they should form an alliance. Horn and Pipey both liked the idea, although, as Horn pointed out, there's an alliance in nearly every object show. The alliance crossed the finish together.
In A-MAZE-ing Plan, Soccer Ball paints a picture of the alliance while the Rabbits are at Box Time. Later, during the contest, when Water Balloon is splitting the contestants up in groups to explore the maze, he keeps the alliance together, and they stay together during the rest of the contest.