The Angry Watermelon is a large watermelon with eyes, seen in the game Virtual Boy Wario Land. Two are seen in Stage 9, where it either blocks the entrance into the next area, or hides the entrance to a door. Similar to the Big Blob, it's found sleeping and is immune to all of Wario's attacks.
In order to destroy the first Angry Watermelon, Wario must retrieve a regular watermelon from the Honey-Bees in the previous area, who may drop either spiked bombs or watermelons. Wario should then throw the watermelon onto the nearby Spring, which propels the watermelon into the background of the stage. With timing, the watermelon may hit the button moving along the background's conveyor belt. This causes the Angry Watermelon to flash and explode, leaving the player to progress further into the level.
Later in the level, a second Angry Watermelon in seen after another row of conveyor belts. It may be destroyed by dropping a watermelon in each of the two fast-moving baskets using the Watermelon Spring, which causes the Angry Watermelon to flash and explode. This reveals a door to the stage's treasure room, where Wario can collect the sailing ship.
Once defeated, either Angry Watermelon cannot be seen again in that game's save file.