Phineas and Ferb's Halloween Spooktacular is an upcoming Phineas and Ferb movie that takes place in October. I has a running time of 1hr and 30 mins.
From Disney XD:
When Dr. Doofensmirtz builds the Monster-inator, all of the children of Danville get turned into the monsters that they dressed up as. Can Phineas and friends save the day even when their monsters? The only way to find out is to watch Phineas and Ferb's Halloween Spooktacular on Disney XD, follwed by a spooky marathon!
Phineas: Mad Scienctist
Buford: Dead Bully
Phineas and Ferb's Halloween Spooktacular will be released on DVD with One Good Scare Ought to Do It! and other monster-related episodes.