Originally Posted by Tony Stark
To be clear folks, there was never a prosthetic used for Thanos. Thanos was a pure digital creation.
What it may have been a photo of was some test makup for the Chitauri, since there were early rumors that it was going to be the Skrull, and they have the bumpy chin like Thanos.
To suggest this guy had inside information on Thanos being in Avengers is 'iffy' at best.
Actually, Thanos WAS a prosthetic. Daimon Porter played him.