Not exactly one single Digimon, but a collection of the ones Ken had under his control.
To be fair, they never thought that the Kaiser would end up like this – they simply thought he was just going to help them achieve strength like he promised.
But now that they looked at the mess of Digimon parts scattered on that creature's body… was that just his plan in the beginning? To use them for a creature that certainly wasn't any brand of Digimon they have seen… and it definitely isn't human – that was a definite.
Was this really the goal of the Kaiser when he took them in? And did they just fail to meet his standards?