I never joke. Especially when it comes to physical trauma. You will pay or I'll have to resort to other forms of compensation, many of which are much more painful then just paying my fee.
The main (and only) doctor in Junktown, Morbid is a surprisingly competent person. Though located in an old garage, his hospital is fully equipped with tools and medical supplies necessary to save lives, including anti-toxins and radscanners (though Morbid cannot treat irradiation on his own). He is quite professional in his dealings and is willing to share his expertise with other students. Razlo of Shady Sands is one such students, trained in his craft by Doctor Morbid.
Of course, no one is perfect and Morbid is no exception. If someone refuses to pay, the normally professional and calm doctor reveals his unpleasant side quickly, as his bodyguards, Flash and Cougar, explain the folly of not paying what's due.
However, that's not the only problem with the good doctor. The rumors that he is dealing in the dead are true.[1] More specifically, Morbid runs an underground operation where he butchers humans, processing them into meat for "Iguana" Bob Frazier, who uses it to produce "prime choice select".
Blackmail Iguana Bob: Killing Morbid and his team is an optional objective that ruins Bob's operation.
Other interactions
If the player enters the basement and witnesses the butcher shop with Morbid present, they can talk to him. However, Morbid will take their eye in return for leniency. Note that this manifests as a simple crippled eye and can be healed with Doctor. Apparently, the Dweller's eyes regrow.
↑Caravan driver: "{145}{}{Well OK then! It'll pay 400 hubbucks. Which route would you prefer?}" Vault Dweller: "{157}{}{Junktown}" Caravan driver: "{167}{}{Great. Junktown ain't a bad place.}" Caravan driver: "{169}{}{Hear some odd doctor is out that way. Deals in the dead, so they say.}" (FGTCARVN.MSG)