Enter on the left side of the door in order to land on the fish, then Damage Boost to reach the ledge on the right.

Entrance condition:

{
  "comeInNormally": {},
  "comesThroughToilet": "no"
}

Requires:

"Gravity"
"canHorizontalDamageBoost"
"canPrepareForNextRoom"
{
  "enemyDamage": {
    "enemy": "Skultera",
    "type": "contact",
    "hits": 1
  }
}