"Excaliferb" is a book owned by Carl Karl, who read the story to Major Monogram when he was sick. The story was about medieval versions of Phineas and the gang, along with a medieval version of Perry, going against Malifishmertz and his Meatlings.
The book has a dark blue color with the front cover looking like a window. On the front cover is a hand gripping a sword.
- "Excaliferb" (First appearance)