Spray inside of bundt pan with non stick spray. Mix cake mix as directed on the box. You can divide into 3 bowls and add Mardi Gras flavors, then pour in so cake is colored or just pour as is into pan. Bake as directed on the box.
Remove and allow it to cool. Then push one plastic baby into the top of the cake. Then place large plate on top of bundt pan and flip over.
Cake should slide out which will make hole for baby hidden on the bottom now.
Frost with white frosting and sprinkle 3 different sprinkles in different sections on top. Slice and tell people to look out for baby in their slice so they don't bite down on it.