A Memu concept art for Metroid.
Menu (Memu in earlier media) are creatures found on Zebes in Kraid's Lair and as X Parasite mimics in NOC on BSL. They are similar to Mellows and Mellas. In Super Metroid they are found in Maridia. They seem to have been removed in the original game's remake, Zero Mission.
Metroid Manual
"They can pass through rocks and walls. Be careful as they fall on Samus in groups. They are the weakest enemy in the hideout, so it's up to you to destroy them."
1986 manga
"Attacks Samus in a swarm. Be careful, as they can slip through rocks and walls!"
