The base says Ral Partha 1983, but the style is very similar to the Citadel 1981/2 Fantasy Tribe Trolls. A standard bearer conversion by John Blanche was shown in White Dwarf during the early 80s. It has since been released by Ral Partha Legacy as part of their Chaos Wars Kickstarter with two Troll Brats with it.
Sculptor:
Tom Meier
Painter:
Adam Skinner