Half-troll is the term used to describe someone who has descended from a parent that is a troll or half-troll and a parent of any other species. Lelior's mother is said to be a half-troll. While it may only be a "your mother is a" joke, he also doesn't deny it. This would make him one quarter-troll, three quarters night elf, akin to half-night elf.
Artwork from Warcraft III depicting a troll was later reused in an article about half-orcs in Alliance & Horde Compendium on page 72. This would imply a creature of half-troll half-orc heritage.