Dr. Lydgate

Dr. Lydgate was a major antagonist in Once Upon a Time in Wonderland and a minor antagonist in season 6 of Once Upon a Time. He débuts in the first episode of the spin-off series and is portrayed by guest star Jonny Coyne. 
Dr. Lydgate is based on Mary's father from Mary Reilly, and is an allusion to Dr. Hastie Lanyon from Strange Case of Dr Jekyll and Mr Hyde.