Digimon - テイルモン===>エンジェウーモン

It never really made sense to me why a cat evolves into an angel, but I suppose it's hardly the weirdest digivolution.

Gatomon is based on the Egyptian view of cats being divine creatures connected to deities, so the transition to an angel is easier to see from that perspective. This inspiration is more evident in its armour-digivolution, Nefertimon.