| Look out!
"He might strike at anytime, even in a way you may not see coming!"
Unless you want to know when he'll strike next, you may want to be cautious as you read this page.
Ethan Finn was a very close friend of Ferb's when he was little. Unfortunately, he died of lung cancer.
In The Bitterness of Phineas Flynn: Another Story, his ghost appears after Ferb dies and finds himself as a ghost.