Gotham: 10 Most Disturbing Episodes
3. 'Hog Day Afternoon' (S4 E6)
Possibly one of the creepiest villains in Batman's rogues' gallery, Professor Pyg makes his first Gotham appearance in season 4, caught up in Sofia Falcone's scheme to reclaim her father's criminal empire.
We first glimpse him as he butchers an on-duty police officer, and the episode only gets more disturbing from there.
When Gordon is called in, he sees that the killer has placed a pig's head over that of the deceased officer. The investigation soon turns up more dead cops, all left perfectly presented with pigs' heads over their own.
Gordon and Bullock tail the Professor, who has kidnapped yet another police officer, and find their colleague just in time to discover that he's had a grenade placed inside his stomach, the blast of which renders both detectives unconscious.
Waking up, Gordon finds himself tied to chair, face to face with Professor Pyg. After a brief monologue from the creepiest man in Gotham, the killer leaves Gordon in order to slit Bullock's throat.
Bullock may have recovered from the events of this episode fairly quickly, but it took the audience a little longer to get over their first taste of Pyg.