Can mini-bosses appear during chaos trials?

I'm still desperatly trying to get the new "boar" mini-boss in the first survace level. I've not encountered it a single time.

So i've been trying to farm it. I keep doing chaos trials that take me to Ephyra, make it to the city, see it's not there and then reset the night.

I did this for like half an hour today and NOTHING!

... can you even get mini-bosses in chaos trials or am I wasting my time?