Wooks tend to travel in packs, they smell strongly of patchouli and are in constant search for free drugs. One of the defining characteristics is an excessive amount of unkempt hair, usually in dreadlocks.
It is important to make the distinction between a hippie and a wook. Hippies can generally be viewed as positive, optimistic members of society with an idealistic goal for the betterment of society. Wooks are everything that you've been warned about in regard to hippies wrapped into a neat little package.