For one week the loser maintains a daily birdwatching journal, real sightings, sketches, reflective prose, and presents their findings to the league at the draft. The punishment is the sincerity. Many losers report accidentally becoming birders, which the league considers a bonus humiliation.
Budget note: this one costs nothing but dignity, which makes it a strong pick for leagues that would rather spend the pot on the champion than on the loser's downfall.
Seen in the wild: fantasypunishments.com