That's right get a Dremel for him, with a pencil grip attachment, much lighter and easy to control than the big dremel, also if you can find one, try thrift stores, a sewing maching foot peddle, it makes controlling speed of the bit much easier. I love my dremel, I use it to carve and engrave my gourds, in my opinion it is the best invention next to toilet paper!!!
If you wish to do carving on a more long term basis, I would recommend a Foredom system. This will have the primary motor on a stand with a long extended flexible shaft and a foot peddle control. These will last far longer than most Dremels. They are more expensive of course but it is possible to find them second hand at jewelry supply centers open to the trade.
They have the added benefit of many more options than a dremel and they are repairable. The motor brushes can be replaced and bearings as well.
This is typically what most professional jewelers and fetish carvers use.
If you wish to work by hand using traditional techniques, then a set of rasps, files and fine diamond files are in order. They can be relatively inexpensive and allow you to do more traditional styles of hand carving. Also chisels and several types of hammers from a small chasing hammer to several dead blow hammers and a few mallets such as a rubber mallet and a rawhide mallet. And don't forget the sand paper and the beeswax...You can collect a selection of paper from 80 grit all the way to 2000 grits and then use sanding blocks to get to 10,000 grit for ultrafine finish work. Auto paint supply houses are your best bet for this.
Some materials are sensitive to the vibration of a dremel and may easily shatter. In such cases the use of hand tools is more advantageous. This is certainly true of improperly mined pipestone or catlinite. Some other types of fine sand stone are also sensitive to vibration. Others work better with slow steady tool work, like jet.
Be sure to wear proper respiration protection when carving antler. And eye protection. Once you get past the harder exterior, the piece can easily spew the softer inner material into one's face and eyes.
I was actually concerned about the Dremel making it shatter. It's going to be a small carving after all. Carving the 'antler' part of the deer's head was what had me pondering the more traditional means of carving.
I already have a supply of face masks/safety glasses for various art projects. So that part at least is covered.
I want something like one of these.
I'm sure the hand tools will take longer than a Dremel, but again, the vibration would worry me with the antlers.