Sunnycide is an egg-based Shroob and a minor boss in Mario & Luigi: Partners in Time.
Mario & Luigi: Partners in Time
When the Mario brothers get to the dead end of Yoob's Belly, they encounter Sunnycide who has captured the Yoshis and Baby Bowser but Baby Bowser frees himself. The Mario brothers and Sunnycide fight. Sunnycide attacks the Mario brothers by throwing eggs at them which they can jump over or on top of, or getting health from them by sucking them into it's mouth, however the younger Mario brothers can whack it's sensitive part with a hammer. All attacks are useless against it until the Mario brothers free all the Yoshis from the eggs to roll a boulder on it which causes it to fall over and then the Mario brothers can jump on top of it's sensitive part inside it's mouth. When Sunnycide is knocked down it can use chain to pull which creates a hole for the Mario brothers to fall but they can avoid falling by jumping, or it pulls a switch, so it is dark for a Boo to get the Mario brothers, however, the baby Mario brothers can avoid this by whacking the Boo. When the Mario brothers kill it, an entrance opens which can make others leave Yoob's belly causing it to presumably die.
Sunnycide's name comes from the way some people eat eggs for breakfast: sunny-side-up.