I know he made a male Phantom het Clown last season as I asked about them So i'm sure he has made more as he seems to put most things to his Phantoms.
As for a Desert het Clown female.... they have been around for a while (Deserts) so its not hard to imagine him having one hidden away in his racks from 3+ years ago.
Well with this line of thinking, it would resolve a few threads. That female deserts can lay viable eggs and what the Flatline is.