Appearance in Mother
Most often, Momseyes appears in a group of enemies, alongside with one Dadseyes and one Watcher. It is normally the strongest enemy in this group, and will typically inflict the most damage over the course of the battle. Dadseyes is able to inflict more damage per attack if it flies into a rage, however.
Momseyes, Dadseyes, Watcher, Foureyes, and Groucho are clearly related in some way based on their nearly identical appearance, shared location, and very similar Japanese names. However, this relation is never explicitly revealed. The existence of a seemingly disembodied pair eyes acting on its own is never revealed either. All of these enemies are only seen in the bizarre land of Magicant.
"Momseyes will spot you for sure!"