Matilda Rabbit is a minor character in Fatty Bear's Birthday Surprise. She is a stuffed toy rabbit who acts as an adult figure while Kayla is asleep. Matilda is able to use her ears as the propeller of a helicopter to fly.
At the start of the game, Matilda offers to help Fatty Bear bake the birthday cake and Fatty Bear accepts. Matilda automatically leaves to the kitchen and arrives to the kitchen after Fatty Bear arrives into the kitchen for the first time.
After the puppy gets free and Fatty Bear leaves and reenters the kitchen, Matilda reveals that the puppy who was intended to be Kayla's birthday present ran off with some letters for the "Happy Birthday" sign which a doll named Gretchen needed to make on a bulletin board.
When Fatty mixes the batter, Matilda is the one who puts the cake in the oven, and then takes it out. Once the cake is decorated, it is she who carries it off to the bedroom. Matilda remains inside the kitchen until the end of the game.