Trolls have an extremly low chance of spawning with 1-3 babies nearby. Babies aren't nearly as tough as adults, but are still formidable foes. They fight alongside their parent, but will flee once the parent dies. Even lower chance of a baby spawning without a parent, which will always flee when spotted. Loot is pretty much the same as adults, just a lot less of it. Perhaps a new curio, Baby Teeth or something like that.
Troll nests? Also extremely rare and always found abandoned. Can't decide if there should be any use to them or purely aesthetic.