https://en.wikipedia.org/wiki/Santa_Claus's_reindeerfinal two, "Dunder" and "Blixem", are from a Dutch oath meaning "thunder" and "lightning"The german is correctly Donner und Blitzen
"Dunder and Blixem!". ;)
https://en.wikipedia.org/wiki/Santa_Claus's_reindeer
The german is correctly Donner und Blitzen
Donner and Blitzen came later, 2nd revision.