If you love Adventure Time and rainbow cakes, then check out the most algebraic birthday cake ever made. The cake looks exactly like BMO and contains 6 layers of Lady Rainicorn’s body rainbow colored cake. It was made by Randi Madden for Adventure Time’s creator Pendleton Ward (so basically Glob himself) for his 30th birthday. So if you guessed “Happy 30th Pen!” meant someone was celebrating the 30th pen they’ve ever written with, you guessed wrong.