This is the stuff I love seeing! Solid color use, coherent style that translates well to other units, presumably an entire army. Great use of the old skulls on the shields is the cherry on top! I'm repainting my TK as they were done when I was new at the army painting thing but I've done enough that I won't switch to this theme but I am tempted!
The figure himself looks to be a Tomb Guard, and the banner top looks like it's either from the Bone Dragon kit or one of the Giant skulls in the Citadel Skulls kit, but I'm not sure about the banner itself. The standard unit banner is one from the Orc Boyz kit as I recall.
It looks great but definitely reads more IMO as Lizardmen than Tomb Kings. I wouldn't complain if mine were upgraded to this standard.
Very nice usage of the Oathmark Skeletons there... poor marks for keeping the heads wearing Celtic-style helmets, because though I love the Celts, the inclusion of their aesthetic jars heavily against the Egyptian banner and theme of the army as a whole (and is similarly why I can't stand it when people use the 'Jason and the Argonauts' Wargames Atlantic Greek Skeletons and call them "Tomb Kings")... but can't deny the kit is a great one. My main gaming pal has used some for his new Vampire Counts army and they are much better than most of the other plastic skeletons on the market right now.