The Serpent Emblems are items found throughout stages of all four campaigns during the course of Resident Evil 6. There are 80 Emblems in all, 20 for each campaign. The Emblems take the shape of the family symbol of Derek C. Simmons. A guide for the Serpent Emblems can be found here.
Each Emblem found in the campaign correlates to a specific file in Resident Evil 6 that is unlocked when the player destroys the Emblem, making 80 total files available. For each campaign, when certain groupings of Emblems are destroyed (all Emblems in one chapter, or all of the first, second, third or fourth Emblems in each of the five chapters) they will unlock a figure viewable in the Collections menu. A final figure is also unlocked when all 20 Emblems of a campaign are destroyed.