A regular Nug?! jeez!
i'm scared now... downloading it as soon as I get home! 
Only happens once in a blue moon though. 
Best part of the trials is simply running into a regular mook trash group and finding out there's a big guy with a two-hander in that group which has been upgraded several levels above your own, starts with full guard, high resistances on top of that and starts nearly one-shotting Cassandra with their two-handed mauls.
First time that happened was yesterday on a new character on nightmare. Running around in the Hinterlands, killing some mage/templar groups on my way to the rift and shards, only to find myself in a life or death fight at random with 2 guys like the mobs I described above, a few archers and some mages with sellswords. All were at least my level (only level 4 in this playthrough
) or higher thanks to the trials, up to double my level. Some of which had skills I'd never seen pre-Skyhold. Only to be ambushed by a group that spawned behind me. Really spices things up compared to the usual steamroll. Managed to survive by using 7 potions. Some boss fights I've had in this game are tame compared to this fight. 
I'm actually checking out groups in tactical camera before engaging them if groups are bunched up, as not to run into any nasty surprises. Haha.
Don't think I want to know if this trial can upgrade dragons and giants too. 