The Shadow Mogadorian is an Augmented Trueborn Mog. He has the power of teleporting into shadows and using them to his ability. He makes his presence for the first time during the attack on Patience Creek. He was responsible for bringing in the many Mogs during the attack. John had scanned the area before landing - being seemingly alone, he detected no threats - but soon Mogs appeared from everywhere.
"He wraps his arms around Phiri's waist and yanks her backwards, the shadows like liquid around them, swallowing them up." (Four)
The Shadow Mog is younger than the other Augments John first encounters at Patience Creek. He's deemed a few years older than Adam.
Besides teleporting himself, the Augment could bring in Mogs from elsewhere by apparently leaving behind portals in the shadows. They could use these when he is not present, though it is unsure how long these portals would remain open and how far they reach.
"But then I see one step out of a shadow - literally step out from where there was nothing before - and I realize that they're teleporting in somehow." (Four)
The Augmentation is unlike Number Eight's Legacy Teleportation. It is shown that Eight can teleport 200-250 feet, without the enhancement provided by a large Loralite stone. It is also stated that the farther he teleports, the worse his accuracy is, and he can teleport with a maximum of two people at once.
It also seems the Mog is powerless as soon as there are no shadows present to teleport into; when Sam Goode commands the lights to go on, the Mog can no longer use the shadows to teleport his lower body back. He dies at the hands of Sam and Four.