Warning: spoilers below.
There's a certain theory that's been making the rounds since 13 Reasons Why debuted at the end of March - no, not the one about Tyler and Alex. This one involves Tony, your favorite greaser. While he's positioned to be Clay's metaphorical guardian angel in the series, some people think that his angel status is literal, claiming that he could be a ghost.
I get it; he drives a cool, old car, dresses like he's from the '50s, and generally seems like a character out of My So-Called Life's Halloween flashback episode, but that doesn't mean that he's a ghost. In fact, this theory occurred to me early on but then was immediately disproved by the fact that Tony interacts with a number of people besides Clay. He talks to Clay's parents, as well as Hannah's parents. He takes the physical action to hand Hannah's parents a copy of the tapes in the final episode. He has a number of scenes with his boyfriend, who is maybe, probably, definitely, not a ghost.
Tony is not a guardian angel. He's not dead, and he's not a figment of Clay's imagination. Can we just agree to toss out this theory now?