Leo Marvin

"You've ruined my life! You've ruined my career! You've ruined my book! You've turned a perfectly peaceful house into an insane asylum! GET OUT!"

- Leo to Bob Wiley

Dr. Leo Marvin is the main antagonist and anti-hero in the 1991 comedy film What About Bob? He is an egotistical psychiatrist who thinks that his psychiatric patient Bob Wiley is crazy. He was played by Richard Dreyfuss.

Plot
Leo is a modestly successful but incredibly arrogant psychiatrist with a wife named Fay, two children named Sigmund and Anna, and a sister named Lily (whom he deeply cares for). He is looking forward to his upcoming appearance on Good Morning America so he can promote his new book Baby Steps, but before he can head to his vacation home at Lake Winnipesaukee, New Hampshire, where the interview will be conducted, he is asked to treat Bob Wiley by a fellow psychiatrist (whom Bob has driven insane). He was about to leave for his vacation, until his secretary told him his final patient Bob Wiley is already arriving. Leo meets Bob, but quickly grows bored of the man's numerous phobias and simply gives him a copy of his book called Baby Steps before sending Bob on his way. Bob was unaware that Leo was going on vacation, but Leo told Bob that he will return until Labor Day and his colleague will cover for him, if Bob needs anything. He then heads to Lake Winnipesaukee with his family. Unfortunately, Bob has developed an idolization of Leo. After various unsuccessful attempts to call Leo over the phone, Bob hatches a clever scheme to figure out where Leo lives and heads to Lake Winnipesaukee to meet with Leo, much to the latter's annoyance.

Upon meeting Bob again, an exasperated Leo simply tells Bob to wait at a local coffee shop where they can talk over the phone. However, the owners of the shop, the Guttmans, drive Bob to Leo's house due to bearing a grudge against the arrogant psychiatrist for buying their dream house after they'd spent years saving up money to buy it themselves. Seeing how desperate Bob is, Leo gives Bob a prescription telling him to take a vacation from his problems. Bob seems to have made a breakthrough, but the next morning shows up and says that he decided to take a vacation both in spirit and in fact, and that he is a guest of the Guttmans who suggested that he visit as a friend. Leo's family takes a shine to Bob and welcomes him into their home, but Leo thinks that being friends with a patient is beneath him. Bob arouses Leo's jealousy by proving to be able to help Sigmund and Anna with their problems better than he can, such as helping Anna deal with her social problems and helping Sigmund get over his fear of diving (something Leo had been attempting for years without success). A jealous Leo pushes Bob into the lake, but Bob brushes it off as an accident. At dinner, Bob continues to praise Leo, but a comment about Baby Steps causes Leo to choke on some food, and Bob performs a painful and preposterous variant of the Heimlich manuever to save his life. A thunderstorm forces Leo to let Bob spend the night, where Bob continues to bond with the kids and Fay. Leo tries to tell his family that Bob is crazy, but they ignore him.

The next day, Leo tries to get Bob to leave before the TV crew arrives, but fails, and the interviewer asks Bob to comment on Baby Steps. Bob gives a glowing report on it and ends up stealing the show while Leo can only make a fool of himself. After the TV crew leaves, Leo throws a temper tantrum and tries to have Bob committed to a mental asylum, but is forced to retrieve him after Bob easily proves his sanity by befriending the staff and other patients. Halfway back, Leo abandons Bob in the middle of the road, but Bob easily hitches a ride back to the house while Leo faces several obstacles, including getting cited for speeding by a motorcycle cop (who recognizes Bob as the man he saw on TV), getting a flat tire, and getting splashed with mud. Upon making it back that night, Leo is surprised by a birthday party his family and friends had been planning for him, including the arrival of Lily, much to his delight. However, when Bob appears and puts an arm around Lily, Leo becomes enraged and attacks Bob, ruining the party. Even after this, Bob still doesn't realize that Leo can't stand him.

Finally realizing that Leo dislikes Bob, though they don't realize why, Fay and the kids reluctantly ask Bob to leave; he sadly complies. Leo, unaware of this, breaks into a sporting goods store and steals a shotgun and twenty pounds of explosives. He easily kidnaps Bob due to the latter being afraid of the dark and ties him up, sarcastically calling his actions "death therapy - a guaranteed cure." Bob, failing to understand the sarcasm, easily unties himself using what he learned from Baby Steps and, thinking that the explosives are a prop, returns to the house and places them inside before reuniting with the Marvins outside, proclaiming that the "death therapy" completely cured him. A shocked Leo demands to know where the explosives are, and Bob informs him just as the explosives go off, destroying the house. Leo is so shocked by the sight of this that he is rendered catatonic.

Sometime later, Leo's family visits him at the same asylum he tried to send Bob to, and they try to comfort him. They later bring him to Bob and Lily's wedding. Right after the priest pronounces Bob and Lily man and wife, Leo regains his senses and shouts "No!" His terror at now having Bob as a brother-in-law (as his objection came too late) is lost on everyone else, who are delighted to see that he has recovered. A brief epilogue reveals that Bob went back to school and became a psychologist, eventually penning a huge best seller titled Death Therapy, and that Leo is suing him for the rights.