The Cake

The Cake is an "unreasonably bad-boy battle automaton" (A giant, piloted robot) created by Gumbald as a magnum opus to defeat Princess Bubblegum and her army.

Appearence
The Cake is extremely large as it surpasses the size of a Gumball Guardian. It appears to represent a wedding cake with features of knight armour. The Cake's two main weapons are a giant mace and a candle which fires a powerful laser but it is also able to wrestle and punch enemies, as it was used to assist the Gumball Guardians to stop the (currently unnamed) corrupted candy monster

Battle Use
Although originally built to fight Bubblegum's army, it ended up being used to help save the world when GOLB invaded Ooo whilst being piloted by Lolly. It assisted  the Gumball Guardians to contain the corrupt candy monster. However, after the first Guardian was defeated and the other one corrupted by GOLB, It struggled and was eventually destroyed.