Tiny Jim

"The last thing I have to do is to squish Tiny Jim while watching TV."

—Greg Heffley talking about Tiny Jim

Tiny Jim was one of Manny's imaginary friends in The Third Wheel, he appears to be always sitting on the couch and Greg has squished him many times, its exactly unknown what benefit he gives Manny.

Greg checking if Tiny Jim is on the couch or not.