- "Desperate to be embraced as sweet and delicious. Prefers to veg out underground as much as possible."
- — Battle Memory
The Yammonster is an enemy in Mother 3. They can only be encountered in Chapter 1 in the Sunshine Forest when it is on fire. They do not move from their position, but they stay underground until a character approaches it, causing it to put its whole head above-ground. After the fire is put out by the rain, the Yammonsters are replaced by the stronger Baked Yammonsters, who in turn are replaced with their strongest version, Grated Yammonsters, from Chapter 4 onwards.
His battle sound is Battle Sound 23 which falls under Code Numbers 505 for regular attack, 506 for Smaaaash! and 507 for Miss. He is the only enemy (excluding the unused enemy Straw) to have this battle sound.