Button the hippo celebrates 21st birthday

Button the hippo, our friend at the Adventure Aquarium is celebrating a huge milestone.

Button turns 21 today!

The birthday bash is happening at Hippo Haven at the Adventure Aquarium in Camden, New Jersey.

Button, whose nickname is "Butt-Butt," enjoyed a cake made of watermelon, cantaloupe, strawberries and some icing made out of broccoli and banana puree.

The celebration will continue through the weekend until Sunday at the Adventure Aquarium.