Jasper is the so far only named relative of the renowned Troll businessman and pillar of the silicon community, Chrysoprase. He is famous for becoming the first and so far only Troll pupil at the Assassins' Guild School. Whilst the vexing quetion of his admission caused no small angst among the Dark Council, the decision to admit him is believed to have been eased somewhat by his uncle making a most generous donation to the School, to enable the establishment of brand-new state-of-the-art Alchemy labs. The names of his parents are unknown.
The German translation of the Discworld's Assassins' Guild Yearbook and Diary 2000, for some reason, calls him F.D.R. Hauer. The note on his progress at the School names him as the only graduate Troll Assassin and notes his successful completion of a Guild contract on an unfortunate Mr Marble. The Inhumation weapon is cited as a sledgehammer, and it is noted that Hauer/Jasper performed the deed in the dead of night as the unfortunate Mr Marble left a pub. Being a diligent and mannered pupil, Jasper returned the corpse to the Guild as proof of his completion of the contract, and as it was night, he discreetly slipped it unter the door so as not to disturb anyone. Fellow Assassins returning from a pub-crawl assumed it was an ornate new doormat, and the error was not rectified until the following morning.
Hauer is the German for "shaper of stone, stonecarver, Hewer. This makes sense...