Ursula Lettuce is the rabbit-like BioBuddy partner of Bree Davenport. Ursula often can be overbearing towards Bree like a mother, which can lead to fights, but they quickly reconcile. Compared to the other BioBuddy, Ursula has the most faith in Bree's abilities. However, this faith can be viewed as "overestimation", as she & Nick Cheetah will often clash with each other when it comes to the performance of either Lab Rat. She has a habit of saying "Roger rabbit" as opposed to just "roger".