Mayonnaise or Milkshake. Caused by homogenizing the oil and water through the oil pump.
Takes a goodly bit to do that.
Cracked head, cracked block, defective new head gasket.
Pull the plugs, fill radiator, pressurize radiator at cap with proper tester, not exceeding manufacturer's specifications, leave it sit like that for 5-10 minutes. See if the gauge on the tester moves.
Then, using an assistant, and OUTSIDE, have assistant watch the plug holes, NOT in line with them, and crank it for a couple of revs only. Have him tell you which hole the hater shot out of. Give you an idea where to look. If no oil, and no steam-blasted-white plugs, lower end, possibly a crack, don't know of any coolant jacket gallery plugs in the crankcase, but never know...