The Attack Synth is a synth cut from Half-Life 2. It was to have nine possibly sensory organs on its forward surface and six weapon barrels on each side. It was to also be a boss as it was to be as big as a Strider though much more armoured.
The synth had legs very similar to the Strider's legs, albeit the Strider having much thinner ones. Its four claws holding the synth in order for it to stand were also present in some iterations of the cut Combine Synth Elite Soldier.