Yukbarfs are an alien species in the Spaceman Spiff universe, featured in a single Sunday strip. The Yukbarf specimens featured were sentient, tall masses of dripping green ooze. In the strip, they captured Spiff after he crashed his spaceship on a distant planet, and a high-ranking Yukbarf took him to a dungeon for torture and presumably interrogation.
The design of the Yukbarfs is similar to one instance of the leaf pile.