i don't have a definitive "worst" injury as i tend to be pretty lucky when it comes to crashes, hits, etc. but here are a few noteworthy ones
summer 2017, slipped on sand on a giant yoga ball some friends and i buried on the beach trying to do a gainer a second time and fell onto my head. knocked me out for a few seconds and my gums were torn up bad - guess i bit them on the landing - i don't remember the 5 seconds leading up to the bail. obv got a minor concussion and my teeth hurt for a couple days
fall 2016, smashed my right knee against a concrete wall; the friction tore the skin off (looks pretty cool as a scar ngl). bled like hell and i had to stop it with leaves since nothing else was around at the time. walked 1 mile uphill in downtown gr to get to my friend's car where he had a medkit, got a lot of weird looks walking around all nonchalant with a big bleeding hole in my knee lol
fall 2013(?), worst hit i ever took in a fight was a tornado kick to the back of the neck, the guy's foot slid up around my ear and tore it at the base a bit. surprised i wasn't out after that
summer 2011, got flung 15ft off an atv and landed on a log back-first, knocked the wind out of me harder than ever in my life but surprisingly no broken bones