Credits to Proxy Lionheart from TrueAchievements for this one, very helpful.
You will gain this achievement upon shooting your last Serpent emblem.
There are a total of 80 emblems you have to shoot.
NOTE: During the Chris and Piers and Jake and Sherry's campaign there are a few emblems that will require a certain character to get them.
Chris and Piers.
Chapter 2 Emblem 2 Piers only
Chapter 4 Emblem 4 (Can be gotten by both characters but Piers is easier)
Chapter 5 Emblem 1 *EDIT The 5 - 1 emblem which Chris can get while crawling through the fan vents can be acquired by Piers as well.
To get the emblem as Piers, first get boosted across the gap by Chris, then proceed towards the second switch that turns off the second fan that blocks Chris' path. While heading this direction, be looking down. You should be able to see it below the floor in the top right corner of a floor grate you can see through. Shoot through the floor grate to collect it.
Posted by TheMasterSpark.
Jake and Sherry.
Chapter 1 Emblem 3 (Can be gotten by both characters but Sherry is easier) Jake can get emblem, Flash grenade will work too, Thanks to TheOceanic815
Chapter 3 Emblem 1 Jake only
Chapter 4 Emblem 1 Sherry only
If your playing on Co op both will need to shoot the emblem in order for it to count.
The timeline
0.00 Leon and Helena campaign starts
5.52 Chris and Piers campaign starts
11.17 Jake and Sherrys campaign starts
17.31 Ada and Agents campaign starts
This is not my video nor do I own it.
This video was uploaded by XCV //