This article or section contains information derived from Co-op Missions, and should not be considered part of the official StarCraft storyline.
The tesseract cannon is an advanced variant of the photon cannon enhanced with xel'naga technology. It could phase itself to other locations, taking its weapon and shield with it. In the alternate timeline where Zeratul survives the opening stages of the End War, the dark prelate deployed them against Amon's Forces to support his army.
Tesseract cannons are the static defensive option for Zeratul in Co-op Missions. They cost 250 minerals compared to the 150 of regular photon cannons, but can be upgraded to give themselves a phase shield and temporarily relocate to other areas, taking their shield and weapons with them, but leaving the base structure behind.
Projects the Tesseract Cannon or Tesseract Monolith to a target location for 60 seconds, transferring all of its shields and its weapon. The Tesseract Cannon is deactivated while this ability is active.