Loki

The Loki was an experimental terran battlecruiser. It was present at Valhalla.

Game Unit
The Loki appears in the StarCraft II: Wings of Liberty mission, Engine of Destruction. It is located in the fourth base on the right side of the map. It is dormant and invincible until a player unit moves next to it. The battlecruiser will attack units in range but will not chase for long before returning to its default position.

Abilities
The Loki has a "liftoff" ability which grants it movement. It does not have a land ability, but appears to have a "dock" ability which accomplishes the same thing.