Milton's age is never specified, though it hovers around 70 and 80. In the Wonder Boner prank call, Milton claims to be 117 years old. He has two children named Chauncey and Estelle and is divorced, though he still meets with his divorced wife at Thanksgiving, most likely on visitation rights involving his two aforementioned children. He has been frozen, injured, arrested, placed on parole multiple times, and presumably killed, though he always returns in preceding calls alive and unscathed.
Milton is diagnosed with ADD which often causes him to get in trouble. Due to a previous arrest, he has a curfew due to parole conditions that forbid him from being out too late on the road. Over the years, Milton has been attacked by many demonically possessed objects such as a demonic Furby, a cable box, and a toaster oven, though this may be since in a reverse prank call to an auto club, he mentioned that he was a witch and a member of the "Devil Tribe", as well as mentioning that he was "possessed by Satan".
He uses a Hoveround, despite being able to run up a flight of stairs. Milton apparently has a glass eye due to a batting cage accident involving Chauncey several years ago. He lives at 1413 Flika-Flaka Lane in Tampa, Florida (an Iroquois Native-American name according to Milton himself), which he claims is named after Christopher Columbus' brother-in-law. His zip code is 41111 and his phone number is 75. According to Milton, he received the 75th phone number in the USA in 1887. In the Y2K Survival Kit prank call, Milton says that he's from 1412 Flika-Flaka Lane in Corbin, Ohio and that his zip code is 42705. In the Furniture Fiasco prank call, Milton says his phone number is 76.
Milton apparently had a job at a bank in a place known as Fletcher (a city or a shopping center) as a bank teller where he had a very unfortunate accident where his crotch got caught in a pneumatic tube that ended with him getting an penile implant; it has been presumed that he retired. He occasionally brings up that his doctor is Dr. Kevorkian when in a situation involving death or pain, most likely a reference to Dr. Kevorkian's practice in assisted suicide.
Milton has been shown to favor shipping things by mail, but is not that intelligent in doing so. He first sent his son Chauncey in a box to the latter's grandmother in Albuquerque and then Milton shipped his late mother's body in a refrigerator box from Kalamazoo, Michigan to Okeechobee, Florida, losing track of both in the mail each time. However, it could be presumed that the packages eventually arrived to their destination since Chauncey is mentioned as a present in later calls.
Milton can be very hotheaded, often calling people while being angry (sometimes to the point of being hysterical) and cursing them out. He seemed to have a overwhelming fear of the infamous Y2K problem, buying kits and calling a toilet company over a tabloid about how certain toilets wouldn't work on the day of the Y2K disaster.
Milton has been known to have several pets and they have been mentioned from time to time in the calls. Some of Milton's pets include:
- Curline (a gopher)
- Harriet (a beaver), named after Harriet Miers
- Horace (an iguana)
- Lumpy and Mumpy (gerbils)
- Moogie (a squirrel)
- Precious (a dog)
- Scooter (a meerkat)
- An unnamed monkey
- Some unnamed puppies