What do mino's drop thats so worth while?

Ive been farming trolls and doing fine but I was wondering if it was worth my time getting to elona? All the bots are there so whats so worthwhile?

I remember people use to farm Minotaurs for their horns, then they would take the horns and trade a collector for some Mesmer mask-- salvage the mask and you would get a large amount of some material and I don't remember which.