Yes, the deer of Nara are alot of things. You can find them under MUST-SEE, under LOCAL CUSTOM, and also under TOURIST TRAP.
They are aggressive, they are cute and they demand you fork out money to buy those deer biscuits from the many "senbei" vendors.
Unique Suggestions: Take pictures of other tourists forking out the money to feed these cute critters.
Take pictures of other tourists being pursued all over the park by these very demanding deer.
If you don't look like you are going over to a senbei vendor, or smell of senbei, the deer will leave you alone.