You'd think John Krasinski would think twice about starting a prank war with Jimmy Kimmel.

Last night, Kimmel revealed that his Christmas tradition involves pulling a prank on his neighbor John, who has retaliated with pranks of his own. "Around the holiday season I have a tradition, and that tradition involves vandalizing my friend John Krasinski's home," Kimmel explained on his show Jimmy Kimmel Live.

Who started it? According to Kimmel, Krasinski did after he was given a key to the late night host's home. Kimmel said "Under cover of the night, they [Krasinski and his wife Emily Blunt] snuck in and they set up this light-up Santa Claus and Snowman in my living room, which was alarming when I got home. They also put a Star of David outside my bedroom, in case I converted or something, I guess."

Kimmel is not the sort to let something like that go on without retaliation. He shared the following years of pranks: hanging up a neon insurance sign on John's home, buying a 30-foot inflatable reindeer and putting it on his lawn along with some reindeer poop.

However, this year Kimmel pulled off his biggest prank - and did it earlier in the year so he could get away with it. Check out what he had a crew do to the actor's home in seven hours in the video above.