When he was older, he served in the RAF, was shot down and held in a POW camp.

Due to Donald's looks with his features, balding and his voice he was often typecast by playing strange or menacing characters for British TV shows and movies. He became a very popular character actor due to all of this. He played Prince John in the series The Adventures of Robin Hood which he got alot of credit in. His most memorable character was the role of Ernst Stavro Blofeld in the 1967 James Bond film You Only Live Twice which decades later would influence the Dr. Evil character in the Austin Powers films as both character have a large facial scar.

He was very much a versatile actor acting in all sorts of films and TV shows including family, war, crime, thriller, comedy and sci-fi, getting credit for each and every one of them.

He started acting in the horror film industry while the 50's were coming to an end along with many other types of film industries too. His first horror film was titled The Flesh and the Fiends which is a twisted cult flick. Pleasance co-starred as a demented assistant named William Hare to a surgeon played by Peter Cushing requiring cadavers for his research into the functioning of the human body and Pleasance's character is his assistant who find ways to provide him with fresh specimens.

Then he won many other roles of similar type character in numerous other cult horror films like Circus of Horrors, The Hands of Orlac, Eye of the Devil, Creature of Comfort, Death Line, From Beyond the Grave, Tales that Witness Madness, House of the Damned, The Mutations, I Don't Want to Be Born, Land of the Minotaur, The Uncanny and Night Creature. Wow that alot I tell ya!

But then he started playing a much different character as a Doctor at a menatal hospital named Sam Loomis in a film that everyone would remember him for titled Halloween in 1978 written and directed by the legendary John Carpenter, which also launched the career of Jamie Lee Curtis. In the film, he plays a shrink of a child psychopath named Michael Myers who murdered his sister on Halloween night in 1963 cause it was his inbreed to kill his family as an evil power that night told him to do so. The night before Halloween in 1978, Michael escapes from the hospital and steals Lommis' car to return to his hometwon of Haddonfield as he finds out that he has a biological sister named Laurie Strode that's played by Jamie Lee Curtis. Loomis tries to track him down as he ends up on a killing spree on Halloween night each year as Pleasance reprises his role in each of the sequels until part 6 when he was suffering from his illness.

He worked with John Carpenter a number of other times too and had a similar name from his Halloween character in the 1987 flick Prince of Darkness (An awful film) named Father Loomis of an abandoned church in Los Angeles that has a sinister secret which was kept in the basement for many years. They find a green liquid that poisons people there turning them into zombie type demons as the liquid is contains the essence of Satan himself, and they also discover that he will release HIS father - an all-powerful Anti-God!

He acted in many lower budgeted horror films throughout the 80's and 90's due to his fame in these films. A couple of them were based on Edgar Allen Poe's books as he travelled down to South Africa to work on them. The first one was titled The House of Usher, a story of a couple going to visit one of their uncle, Roderick Usher, at his mansion. They find, however, that Roderick's brother Walter (Which Pleasance plays) has gone insane, and Roderick himself isn't far behind and finding it difficult for them to escape. Roderick was played by Oliver Reed which Donald has worked with many times before in the UK.

The next one was titled Buried Alive, a tale of a bunch of disturbed teenage girls at a Ravenscroft Institute which people called a spooky girls' school but suddenly they are fallin into trap doors and a masked killer is walling them up behind brick walls. Pleasance plays the role of Dr. Schaeffer who helps out at the institute but has a dark secret himself. The film also starred Robert Vaughn as the head of the institute named Gary, A debut performance by Nia Long as one of the clients named Fingers and former porn queen turned scream queen Ginger Lynn Allen as the nasty client Debbie who gets what's coming to her in the end. The film also had a special appearance by the late horror icon John Carradine. The film was shot before his death and then shelved away but went direct-to-video in 1990.

Donald also worked in films down in Italy where the horror industry is really big. His first horror gig down there was a 1985 one titled Phenomena written and directed by Dario Argento. In the film Donald plays a Professor named John MacGregor who befriends with of a teenage girl named Jennifer Corvino who is a daughter of a famous actor arriving in an expensive boarding school. Jennifer sleepwalks and is capable of telepathy telepathically communicate with insects and has adaptation problem in the new school. This is where Donald's character came in as he meets her while sleepwalking but only to get killed as they investigate a killer who is killing the young girls there.

He began to work steadily there along with the other countries he worked in but his last film was shot there titled Fatal Frames which was an independent film. He had a supporting role named Professor Robinson as he meets with other people about a group of unsolved murders taking place around the city of Italy while making a music video for pop sensation Stefania Stella. Rumour had it while shooting there he died in the middle of the run and had a body double to finish up his work there. There was an online joke on him about his character as Dr. Sam Loomis from Halloween. The film was successfully shown at numerous festivals in 1996 and also sold well on DVD. It featured many local Italian actors but had some supporting roles by American actors like b-film scream queen Linnea Quigley.

Donald Pleasance died on February 2, 1995 in Saint-Paul-de-Vence, Alpes-Maritimes, France due to a complications from heart valve replacement surgery from his illness.

Both films Halloween: The Curse of Michael Myers and Fatal Frames announce before the closing credits to the memory of him. Bless his soul.