Gleipnir

Shuichi Kagaya leads an ordinary life in a sleepy town, but his tranquility is disrupted when a mysterious girl named Clair discovers his secret: he can transform into a powerful, oversized dog with a zipper on his back. Clair is on a mission to find her sister, who killed their family, and she'll stop at nothing to use Shuichi's powers to achieve her goal. As they're pulled into a world of monsters and danger, Shuichi and Clair must work together to uncover the truth behind their powers and confront the darkness that threatens their lives.

You can stream Gleipnir on: Apple TV Amazon Store

Some TV shows that have similar genres and were produced around the same time as Gleipnir include The Owl House, Fairy Tail, Teenage Mutant Ninja Turtles, Scooby Doo, Where Are You!, Victor and Valentino, Darkwing Duck.