I think it would be cool to have a pet or something like that, kind of like a beast master class.
We're definitely going to have summons (duration based); however a full on "pet" would likely be handled better as another party member. Party size is flexible (1-5), so you could certainly run a dungeon as a duo (hunter and his pet).
I know there are limitations for DMs, but having a mode without DM limitations seems like so much fun. (One could, you know, spawn a towl army.)
We're going to try to give the DM as much freedom as possible. Our goal with having the DM work off of pools that are filled through player actions is to make sure that the game still "works." A DM will certainly be able to create or modify encounters, so they'll be able to fill a room with Towls (swarmer difficulty) if they'd like! We'd like to make it so that a DM can only spawn an encounter that would be "very challenging" rather than impossible, given the players' current levels of potency.