Simon Cowell turns 54 today, but his special day doesn't exempt him from being the butt of jokes and pranks by any means.

When Cowell woke up this morning, he stepped out to see his yard and house completely covered in toilet paper. According to TMZ, the girl band Fifth Harmony are the culprits behind the prank. How do we know? The group put up a banner in the yard saying, “Happy 87th Birthday Simon!” along with rolls upon rolls of toilet paper.

Entertainment Wise reminds us that Fifth Harmony know Cowell because they owe all their fame to him – they got their start on his show X Factor USA.

The girls of Fifth Harmony weren't the only stars to play jokes on the birthday boy. Demi Lovato took to Twitter to make fun of Cowell's age. She included a picture of a life alert ad accompanied by the caption, “Can't wait to give you your birthday present @SimonCowell!!"

How do you think Cowell is reacting to all the playful fun?

Image courtesy of Wikimedia Commons