Male fallow deer are called bucks, females are called does and the young ones are called fawns. Does do not have antlers, and this little guy has budding antlers, so that makes him a fawn or a young buck.
Adult males have palmate antlers, which means that they are flat plates rather than the tube-like horns of Red deer. This second photo makes it pretty clear what palmate means.
And look at the jackdaws perched on the buck. They must be picking ticks and other insects off the deer for it to be so calm and obliging about the free ride the birds are getting.