rat tail

Ollie officially has a rat tail and is completely bald on the top of his head...

according to Wikipedia:
rattail is a haircut that is characterized by a long "tail" of hair growing from the back of the head. It saw a notable phase of popularity during the 1980s but can still be seen today, albeit in a rarer form. The individual with a rattail typically has his or her hair cut short all over their head except for a few strands in the back that are left to grow out.
The rattail usually curls naturally; however, it can be braided, treated as a dread, permed, straightened, or curled with an iron. In some instances, an individual might choose to grow several tails or grow a single tail very long. As the hairstyle has become less popular, it has been increasingly associated with redneck culture and is a common characteristic found in stereotypes of lower class North Americans.
The Guinness World Record for longest rattail measures 4 feet 9 inches held by Grant Ruramora.


I dont care what Wikipedia says... Oliver is not a lower class North American!!!