Diary of a Wimpy Kid Wiki



Diary of a Wimpy Kid Wiki

"I've cut up some orange slices for you, sweetie!"
The Grout pretending to be Susan (in Greg's mind)

The Grout is an imaginary monster that Greg Heffley misinterpreted grout as. It is one of his worst nightmares and it is featured in Wrecking Ball as the central antagonist.

The Grout in this bathroom is really nasty!

Greg hearing his parents talking about the grout

Greg's fear of grouts started when he first moved in as he overheard Susan and Frank complaining about the grout being really nasty in the bathroom. Greg didn't know at the time that the grout was the gritty fluid in-between the bathroom tiles and instead deemed it as a immense, hairy creature. Since Greg never got a glimpse of The Grout, he figured it hid itself inside the pipes whenever he strolled into the bathroom; this thought made him anxious over taps and drains. Greg also didn't feel safe in any of the alternative bathrooms around the house as he assumed The Grout would slither through the pipes and grab him there.

Greg is scared to see The Grout in his bedroom while sleeping

Greg thinks the mop and the clothes stacked together are the grout.

Greg attempted to combat The Grout slithering out of the taps by blocking them with balloons; however, this turned out to be a pretty dumb move as when Rodrick ended up throwing a water balloon at him in the house. Greg assumed that he needed protection whenever he was in the bathroom, so he found a grout gun below the sink and started arming himself. Greg's fear continued as he started worrying about The Grout slithering out of the bathroom and entering his room. After a few nights of perceiving The Grout was right in the room with him, Greg finally got the courage to tell Susan; she thought the whole incident was hilarious and she told him to what grout actually was. However, despite that Greg was still afraid as he thought The Grout was impersonating Susan and he locked his room every night.

Greg screams at Frank as he holds a glob of hair from drain

Greg scared by his dad.

Eventually, Greg stopped believing in The Grout however his fear sprouted back up again when Frank pulled out a glob of hair while he was presenting how to do plumbing to him. Greg locked himself in his room and Frank had to unscrew his door off the hinges.[1] Greg's fear continues throughout the book as he fears that the builders might cut through the plumbing and unleash The Grout while connecting their house to the extension.[2] Later, the Heffley family receive the news that they are going to have to supersede the bathroom floor as it's rotten and Greg says they are lucky nothing dreadful occurred while it was in use because he could think of ideas that could've happened worse than The Grout.[3]


  • It is the manifestation of sink drain hair.
  • The Grout pretending to be Susan may have been inspired by The Beldam from Neil Gaiman's Novel Coraline, and the 2009 film adaptation.




  1. Wrecking Ball, pages 74-80
  2. Wrecking Ball, pages 132-133
  3. Wrecking Ball, page 193