It’s not tv, but you could try reading some of Grant Morrison’s (the creative head) comics. The Filth has a lot of similar vibes and is a great intro to their work, and The Invisibles is nothing if not interesting and strange as all hell. It’s easily my favorite of theirs, but it’s also definitely not for everybody lol

Someone else already mentioned Pulp Fiction, so I’ll also add that Reservoire Dogs and Once Upon a Time in Hollywood are a couple other Tarantino flicks that might scratch the itch.

There’s also the Evil Dead series. Movies and TV both, in different ways. The vibes get closer and closer to Happy as the series goes on, with Ash Vs Evil Dead (the tv series) probably coming the closest. Haven’t seen the remake/reimagining, but I hear that it’s more into the horror and gore than any of the others. Probably not what you’re looking for, that one.

Edit: Just remembered that Chainsaw Man exists. The anime is great, but the manga just goes harder (the author’s original style sells it better imo) and has way more content. Seriously, if you like Happy and only ever read one manga in your life, Chainsaw Man is a great pick for that one. They are cooking some crazy, meaningful, and beautifully odd shit thataways