The SideHoppers can be killed safely from behind with Power Beam.

Requires:

"Morph",
{"or": [
  "Wave",
  "canDodgeWhileShooting",
  "h_usePowerBomb",
  "ScrewAttack"
]},
{"obstaclesCleared": ["A"]}

Clears obstacles: C

Dev note: Killing the ceiling hopper is the only one that's not free. Killing the bottom two and leaving the left door is accounted for elsewhere.