Bitsy

What is Bitsy?

Bitsy is a desktop pet with real emotions. She walks, jumps, climbs walls, shoots machine guns, throws bombs, plants gardens, does magic tricks, and has 50+ unique pixel art animations. She gets lonely if you ignore her, grumpy if you fling her too much, and hyper when you play with her. She reacts to your typing speed, battery level, and even knows what holiday it is. Free, open source, no signup needed.

From the website

Dead Pixel Pet

Meet Bitsy — a tiny pixel creature with 50+ behaviors, real emotions, and a personality. Free desktop pet for Windows.