Brain Train

Phineas and Ferb has been brain switch into Timon and Pumbaa including Isabella.

Summary
Phineas and Ferb are building the brain switch, until Isabella, Timon, and Pumbaa came in to check on them. Phineas decided to test it with Timon to switch their brains. After they test it, Phineas is acting like Timon and Timon is acting like Phineas.

Trivia
It's like from the episode "Does This Platypus Make Me Look Fat".