Some links to this title refer to actual, lower-case toymakers.
Talk about it here.
A being or beings, due to different and inconsistent accounts held by Time Lord records, the Toymakers possessed vast mental powers, and could build and destroy entire realms with their minds. (PROSE: Divided Loyalties) All Toymakers were immortal and played games against other beings. If they lost, the beings would be transformed into items and become part of the Toymaker's domain. (PROSE: The Celestial Toymaker)
The only two members of this race to be encountered in the universe were the Celestial Toymaker, often known simply as the Toymaker, and his sister Hecuba, the Queen of Time, who turned people into clocks. (AUDIO: The Queen of Time)
Different accounts refer to the Celestial Toymaker being not only an Elder God (AUDIO: Black and White) but a Guardian of Time, (PROSE: Divided Loyalties) and carrying his own mass, projected from his original universe. (AUDIO: The Nightmare Fair) He was also connected to his Celestial Toyroom, able to step out of it but never fully leave, (AUDIO: The Magic Mousetrap) and were he to be destroyed, he would simply return. (AUDIO: Solitaire) How these characteristics related to all Toymakers is unknown.
Behind the scenes
Both Divided Loyalties and the novelisation of The Celestial Toymaker make reference to there being multiple Toymakers, which was later somewhat supported by the introduction of the Toymaker's sister in The Queen of Time.