Three Amigos (3 アミーゴス) is an unused enemy in Mother 3. It only attacks with what the game says is a powerful punch, despite the lack of damage that said punch causes. It is one of the few unused enemies that gives experience when defeated (in this case, 508 EXP), and always drops a Bag of Pork Chips. The name is likely referencing the Sanchez Brothers from Earthbound, as the brothers are a trio of (likely) spanish brothers.
It's battle sound is Battle Sound 16 which falls under Code Numbers 484 for regular attack, 485 for Smaaaash! and 486 for Miss.