MOSFET voltage is opposite from what I expect
This is what you should get.
If V1 is 0V M1 is turned off so R1 pulls the output up to 12V.
In this state imagine the circuit without M1 present all you have is R1 connected to 12V. There is no current through the resistor so the output has to be 12V
If v1 is 5V M1 is turned on and pulls the output down to 0V.
In this state imagine that M1 is replaced with a short circuit from Drain to Source.