Why does Thanos have a scratch on his face?

This is what happened to Thanos. He happens to carry the Deviant gene, unlike the rest of his family. While they looked a lot like humans, he was born looking like a monster, hence the scars on his face.

Are those scars on Thanos face?

So yes, there are some scars on the right side (his left) of Thanos’ face that resemble Wolverine’s claw marks, but you’ll also notice in other looks at the Mad Titan that not only is the other side of his face scarred, but he has scars all around his body.

Does Thanos have scars?

At the very end of the spot, we get a new shot of Thanos that shows the Mad Titan will be rocking a pretty distinctive scar on the left side of his face in the movie. A scar that looks quite a bit like someone with three claws left a pretty lasting impression on him.

Why is Thanos chin like that?

Where Eternals are generally attractive and peaceful, Deviants are hideous and warlike. Though Thanos was born to two Eternals (A’lars and Sui-San), his body carries the Deviant gene. That’s why he has mottled purple skin and a disfigured chin whereas the rest of his family could more or less pass for human.