Null

From Plane Shift: Zendikar, page 28.

When a vampire who is not a bloodchief drains the blood from a living humanoid, that creature undergoes a horrible transformation, becoming a stronger, faster version of a zombie called a null. Nulls' heads are featureless except for a gaping mouth filled with jagged teeth. Their bodies are shriveled and distorted, but preternaturally strong. They are mindlessly loyal servants to the vampire nobility, and the number of nulls under a vampire's control is a mark of status and power among the vampire houses of Guul Draz.

The stat block for a zombie is provided below. The extent to which a null is stronger and faster is up to a DM.