Cowl — Neal Asher

In the far future, the Heliothane Dominion is triumphant in the solar system, after a bitter war. But some of the enemy have escaped into the distant past, where they can position themselves to wreak havoc across time. The worst of these is the monstrous Cowl, an artificially forced advance in human evolution, more vicious than any prehistoric beast.

Hunting through all the timelines, Cowl's pet, the torbeast, grows vast and dangerous. It sheds its scales where its master orders. They are tors -- organic time machines intended to bring human samples to Cowl. And then the beast can feed...