The Domestobot is a robotic servant mass-produced in the 1980s and still widely referenced in the 1990s in the GTA III Era. In the GTA IV Era, they make a comeback in the late 2000s. It appears to be based on the Tomy Omnibot 2000, though the head is more similar to that of the Nintendo R.O.B.
Grand Theft Auto: Vice City Stories
The Domestobot is prominent in the mission Domo Arigato Domestoboto (set in 1984), Lance Vance plans to destroy Armando Mendez's vault containing his bonds and buys some high-tech equipment that can control Armando's Domestobot, which he bought under the encouragement of Diego. Vic Vance recieved word of the delivery before Lance and decided to take out the bonds using the Domestobot himself. The Domestobot can be driven and is obtainable through cheat devices and third party programs.
Grand Theft Auto: Vice City
Set in 1986, the radio spot for Domestobot aired on Emotion 98.3 and KCHAT. The advertisement informs the listener that it is three feet high, says only ten different phrases, and is a robotic servant.
Grand Theft Auto: San Andreas
Set in 1992, Adam First calls into Area 53 on WCTR to report seeing a group of Domestobots in the middle of the desert while hang gliding. Later on, Area 53 receives a caller going by the name of 632369439, a Domestobot programmed for evil.
Grand Theft Auto: Liberty City Stories
Grand Theft Auto IV
There is also an in-game website devoted to the robot, Domestobotlovers.com.