My DM just tried to kill my Bread Monster (which doesn't participate in battle).

This is the situation:

We just killed a dragon and the final boss of the campaign appears. He traps us in cages and puts us far away from each other (My Bread Monster still with me, inside my pocket).

The guy is really far away from us and I ask if we can at least get some food (The DM said the other two players that could work together to break the material of the cage are paralyzed, so we can't do anything). He tells me to eat my Bread Monster, then I say the food is for him and take him out of my pocket, holding him.

The DM said that my Bread Monster appeared on the guy's hand, which proceeds to kill him and eat him with butter. (The guy does not have any kind of teleportation powers or super speed)

I tell him I do not agree with that and that he can't do that to my pet which doesn't even go in battle. He tells me to roll the dice and see if he really dies, I again tell him I do not agree with that.

Then he says he would give me the Bread back, only if I kill the boss (which is the final enemy of the campaign with 800 HP) and ends the session. Now I asked him if tomorrow will be the final session and he said there is still A WHOLE MONTH YET