Dr. Cat, from Ultima VI
During Blackthorn's reign, Dr. Cat could be found working the bar of The Cat's Lair Tavern, where he offered the usual services of his establishment.
Later, during the gargoyle invasion of Britannia, Dr. Cat could still be found working at the bar of his establishment, surrounded by a number of his feline companions. He felt Paws was the perfect place for him because his tavern was on the King's Way, equidistant between Britain and Trinsic, and well traveled. When asked about the gypsies, Dr. Cat seemed quite fond of Zoltan's traveling band, but had a great dislike for the group north of Trinsic. The bartender even claimed he once had a bet with the gypsy Taynith on whether or not he could catch a duck with his bare hands. Winning this bet, he decided to tie the duck on a string and keep it with him. Talking longer with Dr. Cat further revealed him as a friend of Kytyn of Britain, whom he asked the Avatar to ask about her purr, and the bard Mandrake. Dr. Cat told the hero he was searching for a copy of 'Snilwit's Big Book of Boardgame Strategy', and if the Avatar located the tome, would award the hero 200gp.
The tavernkeeper felt Thindle and Mortude's simple game of flippets lacked the intellectual complexity of his preferred entertainment, nim. Nim consisted of players progressively subtracting 1 - 3 points from 10, a game which ensured Dr. Cat could never lose as long as he played first. The cunning man would take bets as large as 50gp from the Avatar, but was willing to indulge in a game for free.
 Ultima V: Lazarus
Immediately recognizing the Avatar in Ultima V: Lazarus, Dr. Cat was proud to tell the hero that he helped looked after the cats of Paws, and merely ran a tavern as a means of paying the bills, telling the hero how had bought and renamed the Folley Tavern from Rob before the previous tavernkeep moved to a new location. The strangely feline man was enamored with the cats of the town, and spoke at length of his affection for the animals, saying he believed Lord British's virtues should also apply to Britannia's treatment of animals. Still, with Blackthorn's recent rigid interpretation of the virtues with his Ethics, Dr. Cat felt all hope was lost for improving the treatment of cats throughout the land. He believed that Ferru, who benefited from selling his horses to the Oppression and spying for them, was not necessarily an evil man, just one who was ignorant of the true intentions of the Oppression and was blinded by the profit to be made by serving them.
After speaking to Windfer, Dr. Cat mentioned the recent disappearance of his serving girl Kitten, having a hard time understanding would could have happened to the sweet young girl. The distraught tavernkeeper asked the hero to talk to all the citizens of Paws to see if anyone knew of her fate, ultimately learning that the young girl had been arrested due to Ferru's influence. The Avatar could finally discover the fate of Kitten by traveling to Wrong, and there in the first chest of the dungeon was Kitten's brooch. The hero could then choose to tell Dr. Cat that the young girl had been imprisoned and tortured to death. Horrified by this knowledge, Dr. Cat bade the hero to talk to Ferru, and let the stablemaster know the true consequences of his flirtations with the Oppression.
 The Ultima 6 Project
In The Ultima 6 Project, Dr. Cat mentioned that recently a small farmer's home in Paws had been burnt by a suspected Gargoyle war party, and the family killed. Dr. Cat recommended the hero talk to the Tower Guard for more information about the deaths of Dugan, Amarus, and Kier. The tavernkeeper felt that the father Dugan had been an angry sort who blamed everyone else for his problems. With the arrival of the Gargoyles, he held these creatures to blame for his lot in life, and would often get drunk at the tavern and start to belligerently yell about sending them all back from whence they came. Amarus, his wife had been cold-hearted as well, and Dr. Cat noted that none of the womenfolk had been able to develop a friendship with her. Dugan, their child had been disturbed as well. Upon further investigation, the Avatar learned that the family had actually died due to an unfortunate accident, and Dr. Cat felt that perhaps their burning hatred had indirectly led to their death.
Dr. Cat mentioned that Ferru, whom the hero had met in Ultima V: Lazarus, had disappeared shortly after Lord British's return from the Underworld. The tavernkeeper suspected it had been another member of the Oppression looking to silence Ferru. However, he didn't like to talk too much of the past, as the wounds still hadn't healed properly.
If the Avatar brought a book about the fight of Gertan against the dragon Freitag at the suggestion of the warrior, Dr. Cat would be thankful, rewarding the Avatar for the find. Also, after the Avatar won enough times at Nim, he would admit defeat and stop playing with the Avatar.
 Runes of Virtue
In the Runes of Virtue series for the Nintendo Game Boy, Dr. Cat is transformed into an anthropomorphic cat-like creature, whom would offer many useful hints for the hero.
He would also appear again in Runes of Virtue II, where he operated the bar in Jhelom. He at first insisted the hero make a wish at the local wishing well, but after Lord Zellivan's kidnapping, he admitted the crime had been good for business because many citizens now frequented his pub to talk about their loss.
- Dr. Cat is the in-game counterpart of David Shapiro, programmer of the Commodore 64 and 128 ports of Ultima V, and writer for Ultima VI. The character's name is an amalgamation of Shapiro's first two online aliases, Dr. Who and Samurai Cat, and is also his professional pseudonym.
- In The Ultima 6 Project, Dr. Cat will let the Avatar take the first stone every second game of nim. This allows the hero to make considerable gold because they can bet high when they play first, but bet low when Dr. Cat plays first. After losing about 4,000 gold, Dr. Cat will no longer play against the Avatar.
- Dr. Cat. Ultima VI Transcript. Ultima VI. "name, job, indu, inte, pet, mead, thin, play, tayn, snil, visi, paws, brit, gyps, zolt, king, duck, purr, kyty, mand".
- Dr. Cat. Ultima V: Lazarus Regional Profiles. Ultima V: Lazarus.
- Windfer. Ultima V: Lazarus Regional Profiles. Ultima V: Lazarus.
- Shapiro, David. "AMA with Dr. Cat". Reddit. 2012-11-28. Retrieved 2012-11-29.