Slivers are often seen toying with enemies they capture, not out of cruelty, but to fully learn their physical capabilities.

The List

Constricting Sliver

Sliver creatures you control have "When this creature enters, you may exile target creature an opponent controls until this creature leaves the battlefield."

Newborn slivers will sometimes wrap themselves playfully around a human's finger. They grow out of the "playful" part.

Commander Masters

Sliver creatures you control have "When this creature enters the battlefield, you may exile target creature an opponent controls until this creature leaves the battlefield."