Phineas and Ferb — Episode 58: When Worlds Collide

You are watching the episode When Worlds Collide After discovering that a strange planet is hurtling directly towards Danville, Phineas and Ferb set out to avert a disaster, while Buford looks forward to making contact with its alien race. Meanwhile, Dr. Doofenshmirtz hopes to steal the world's largest ball of twine.