That would likely be the same type of motor that is within your reindeer motor. Do you have a picture of your prop? A reindeer motor should have enough grunt to move a foam head and mask.
If you decide to go with a wiper motor and need help with a PVC friendly mount, we have one.Yeah, I suspect I will need to get a better motor. It does sound like the gears are "grinding." The hard part will be trying to mount that heavy wiper motor to the vertical pvc pipe. They don't seem to have any mounting screw holes.