I cant help but wonder if theres actually a way this would be practical in real life...like why not just make a gun without the deer?
My guess is that if you could create a deer that made explosive poop and simply pooped into the magazine then you would have a mobile self-sustaining and reloading weapon. The camoflage is also a plus.
The problem with this though is that the poop would stack up inside the deer if it did not use its gun once in a while, even in non-war siterations.
one solution could be to give the deer a second butt-hole as a backup if the magazine is full, but im not sure how practical this would be economically so Im open to suggestions people.