Accountant-Bot (aka Unit 124 or Jerry) is an automated robot built by The Board for Financial and Bureaucratic Improvement to aid scientists and inventors (in this particular case Doctor Tesla) with massive financial issues and money management. While there are many other robots of Accountant-Bot's model (also called Accountant-Bots) Jerry is unique in that he has the dubious honor of being Tesla's assistant.
As Tesla's assistant, Accountant-Bot's main purpose in his career seems to be both managing the massive, climbing debts Tesla has accumulated over the years and nannying Tesla's fractured, broken psyche as his plans fail and fall apart.
Doctor Tesla has made it no secret that he has no interest in actually ever managing his debt, instead using Accountant-Bot as a bargaining chip with The Bureau Of Pointless Scientific Endeavors to get his account unfrozen so he can continue taking out massive loans.
Accountant-Bot has a wife and three children, whom he never gets to see due to the demanding and time consume nature of his job. Unlike Doctor Tesla, Accountant-Bot is not evil, instead remaining completely neutral. He holds no ill-will towards Gary Gears and the gang, but will help Tesla overcome them if it means keeping his job.
Accountant-Bot does not have legs, instead rolling around on a set of wheels.