Here's a link to all the free themes and avatars. They will be leaving the store on mobile and the web so this is probably the easiest way to get it before
Uncharted 4: A Thief's End Avatar Pack 1 on PS4 — price history, screenshots, discounts • USA
UNCHARTED 4: A Thief's End Nathan Drake Avatar PS4 — buy online and track price history — PS Deals USA
Uncharted celebrates its tenth birthday with free PS4 themes, Uncharted 4 discounts, and an upcoming panel | VG247
See just how different Nathan Drake looks in Uncharted 4 on PS4 - Polygon
Uncharted, Difference between Uncharted 3's and Uncharted 4's Character Models. It takes some time to get used to but … | Uncharted, Uncharted funny, Uncharted game