The subject matter of this article was cut from the final version of an official / canonical source.
The Combine Launcher is a mortar with 6 cannons that was cut from Half-Life 2.
It can be found in the WC mappack demo maps "combine_launcher.vmf" and "combine_gallery_002.vmf", where is it is nearby a Desert Launcher. It is unknown when and where it was to be used against the player.
While the Launcher shoots rockets, the model is that of a flare.