SOLVED. Elementary school/middle school genre, Main character is a large kid who is socially awkward and doesn't talk much. He meets a small friend who is small and does more of the talking. These friends had a variety of adventures. [s]

[Gus]

I read it in the mid 90s to early 2000s. The cover art I remember was the back of the large kid walking through fog with his small friend riding on his back. I'm not sure but I believe the title had a name like Rob and Big but I know that's not it. Time period of book was 90s I believe and it took place in the Midwest I think.

[Andria]

Freak the Mighty?

[Gus]

YES!!! Thank you you're the best. SOLVED

[Dawn]

There's a sequel: Max the Mighty, as well as a film (the mighty, 1998)