Reindeer Names

So, is it "Donner" or "Donder"? I thought it would be easy to tell, just by Googling the name, but it isn't. Seems like both are used. And that's not right; after all, it's a reindeer's name -- it must be either one or the other.
There are performers who have sung about Donner, and have been rewarded either by cash or by applause. Could be they were singing the wrong words. To me, that's a pretty big thing, getting the lyrics wrong. I have committed offences a lot less grievous, and yet paid a much higher price.
I think we can all recall a time when we called a person by the wrong name, or said one thing when we meant another. Verbal miscues, oral misappropriations, misspeaking -- call it what you want, if we do it we pay. I think all those guys who sang about Donner when they really meant Donder should pay. And if that's not feasible, then those of us guilty of oral misappropriations should forgive ourselves and move on.
Except of course if he calls out "Dora!" in the middle of the night and your name is Maryanne.