That's the Spirit

It's Halloween night and the kids encounter a strange boy and his father who are convinced their house is haunted. Meanwhile, Dr. Doofenshmirtz's disdain for grass causes him to invent a "mind-transfer-inator" enabling him to merge minds with a cow and destroy all the grass in the Tri-State Area. Unfortunately, his plan backfires and he transforms into a scary "were-cow" that wreaks havoc any time there is a full moon. It's now up to Agent P to stop him and save Danville.

Perry's entrance to his lair
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Background Information

 * On February 10, 2011, Variety reported that Michael Douglas and his 10-year-old son Dylan will guest star in a haunted house episode. No further information was available at this time, but it was thought to be a halloween special.
 * The episode name was first revealed on Netflix. Confirmed on Zap2It

Production Information

 * This episode will on Disney Channel On Demand on September 30, 2011.

International Premieres

 * November 9, 2011 (Disney XD Germany)

Continuity

 * This is the second episode to not take place during the summer. ("Phineas and Ferb Christmas Vacation!")
 * This is the second time Ferb wears his Frankenstein costume. ("One Good Scare Ought to Do It!")
 * This is the seventh time Phineas and Ferb build a type of house ("One Good Scare Ought to Do It!","Thaddeus and Thor ", "The Doof Side of the Moon ", "Misperceived Monotreme", "Swiss Family Phineas", "Tree to Get Ready)
 * This is the third Halloween-themed episode ("One Good Scare Ought to Do It!"; "The Monster of Phineas-n-Ferbenstein")
 * This is the first episode to have a plot on Halloween.
 * Buford is dressed as a pirate again ("The Ballad of Badbeard")

Cast

 * Vincent Martella as Phineas
 * Ashley Tisdale as Candace
 * Thomas Sangster as Ferb
 * Caroline Rhea as Mom
 * Mitchel Musso as Jeremy
 * Dan Povenmire as Dr. Doofenshmirtz
 * Jeff "Swampy" Marsh as Major Monogram
 * Richard O'Brien as Dad
 * Dee Bradley Baker as Perry
 * Alyson Stoner as Isabella
 * Maulik Pancholy as Baljeet
 * Bobby Gaylor as Buford
 * Michael Douglas as Haunted House Resident
 * Dylan Douglas as Haunted House Resident's Son