"Enbog"

You are thinking of bög. It's not even pronounced the same..

wtw was it a rare cat with gleaming eyes in dark or is it something else?

If the word is neuter than you use et other wise en. You have to memorize which words are which because they don't always work nicely.

Yes, et aeble -> an apple, en bjorn -> a bear

Ooooooottttttty