"Even household carpets aren't safe from this guy's smaller cousins. Osohe just houses the big ones."
Battle Memory

Carpet Monsters are enemies in Mother 3. They are first encountered by Duster in Chapter 2 in the Osohe Castle and later in Chapter 4 by Lucas and co. They are found moving slowly under the carpet outside the Ghost Knight's room. In battle, they are weak to Duster's Wall Staples.

It's battle sound is Battle Sound 16 which falls under Code Numbers 484 for regular attack, 485 for Smaaaash! and 486 for Miss.