From Creatures Wikia
The Ugly Tomato is a weed found on the middle level of the Grendel Tree in Creatures 1, near the dock. The Ugly Tomato has negative effects on a creature's sex drive. It also contains small amounts of adrenaline (which can age a norn through increased stress) - it can serve as a form of birth control, or, in times of need, as a basic food source. Compare with Ugly Tomato Herb.