As a person who is both obsessed with animals and FH, I think I have to say...
Yes. A lot, yes.
lots of yes's.
Sometimes just very, very random flashbacks.
I don't think I've ever had a FeralHeart dream.
I don't often remember/have dreams so I could've I dunno.
But if I did have one it will most likely me just sitting at Grounds being a potato.
Funny this thread pops up, because I've had several dreams of FH, it being a big part of my teenage years.
I remember one specifically, in which I actually slept-walked and slept-talked as well. It was in 2013, and I got out of bed, walking over to my parents and explaining to them that I had to be at a FH Summer Party. At the party, I explained there'll be toast to eat, and that I was excited with hanging out with all my friends in the game back then. I only remember that one in small detail, and other dreams would be various little ones about the game, nothing too detailed.