I agree it is spelled Donder in the poem, but the real question is did Clement C Moore (or his printer) know how to spell correctly in German?
The two reindeer names translate to Thunder and Lightning.
Donner is German for Thunder
Blitzen is German for Lightning
(There is no Donder in the German-English dictionary)
The two reindeer names translate to Thunder and Lightning.
Donner is German for Thunder
Blitzen is German for Lightning
(There is no Donder in the German-English dictionary)