Momijis are Galaga satellite (sometimes called a maple). They only appear in some challenging stages alongside Tonbo (dragonfly) and Enterprise (mysterious blue spaceship). Momiji sattelites don't attack in the original Galaga, but in Space Galaga and Galaga Revenge, Momijis appear in formations and waves, and unlike the original Galaga, they drop down and attack. Think about when Momijis are equipped and armed with cannons and weapons.