Call them whatever you like to call them

[Aleksandr]

You are partially correct, Ultima Online your characters were usually refered to as 'chars', but other graphical muds like The Realm and Neverwinter Nights people called them toons. In Everquest Online Adventures they used a lot of terms like char, av/avatar, and toon. The majority of the crowd using the term toon played The Realm, Neverwinter and to a lesser extent M59.

if you are referring to the old Bioware community Neverwinter and Neverwinter 2 (The former made by obsidian) the multiplayer persistent world servers are still up and active and still lack the term 'toon'.
a list of a few hundred active servers may be found at: http://www.nwnlist.com/