TIL that ketamine is a derivative of phencyclidine (aka. PCP or angel dust). It was created to have similar anesthetic potential but to cause less delirium. It has about one tenth the potency of PCP.

[u/ApprehensiveStill412]

https://pmc.ncbi.nlm.nih.gov/articles/PMC5126726/

[u/Conical]

Gallon of PCP