>>31554500252 Atk Choice Band Krookodile Earthquake vs. 252 HP / 252+ Def Aggron in Grassy Terrain: 112-136 (63.2 - 76.8%) -- guaranteed 2HKO after Grassy Terrain recovery.
Given that it has no reliable recovery, I still wouldn't be letting Aggron take 4x SE attacks if I could possibly avoid it. If you were talking about Mega-Aggro, well, it loses the rock type and gains filter, it was already pretty unfazed by earthquake.