Watermelon (Yoshi's Island series)
From the Super Mario Wiki
Watermelons, also referred to as green watermelons, are normal watermelons found in Super Mario World 2: Yoshi's Island, its remake Yoshi's Island: Super Mario Advance 3, its sequel Yoshi's New Island, and Yoshi's Woolly World. If Yoshi swallows the watermelon, Yoshi can spit up to 30 seeds. Ukikis have many watermelons, some half-eaten, which they use to spit seeds at Yoshi; if Yoshi grabs one of these, they will only give Yoshi 10 seeds to spit. The seeds have the same effect on enemies as an egg.
Yoshi and a Bandit duel with spitting watermelon seeds at one another in the Mini Battle Game, Watermelon Seed Spitting Contest. Whoever spits the most watermelon seeds at one another until one's HP runs out as shown on the HP bar wins the minigame.
The Super Green Watermelon Special Item is available in Super Mario World 2: Yoshi's Island and Yoshi's Island: Super Mario Advance 3, and which gives Yoshi as many as 90 seeds. The All-you-can-eat watermelon! Power Badge in Yoshi's Woolly World automatically places a watermelon in Yoshi's mouth, allowing him to have its ability at nearly any point.
Yoshi's Island: Super Mario Advance 3
Names in other languages
Super Green Watermelon