Where does “katte” come from?

katte (Old Frisian) comes from Proto-Celtic kattā, from Proto-Germanic *kattǭ, from Latin catta, from Latin cattus — a cat.

Ancestry of “katte”, step by step

Step	Language	Word	Meaning
1	Proto-Celtic	kattā	cat
2	Proto-Germanic	*kattǭ	—
3	Latin	catta	a cat
4	Latin	cattus	a cat

katte — Etymology, Origin & Word History | Etymology Explorer