"A creepy doll used for black magic. Each one in your inventory gives you a 1% boost to your attack power."
The Boxer Effigy is scattered all throughout the End of Zoe DLC, but once equipped, they give Joe a 1% increase in attack power. There are at least 20 that he can collect, 16 regular and 4 champion. For most, they are set to spawn in a certain place. However, there are a few found in boxes that can spawn anywhere.
As said above, there are some effigies that may spawn differently for each individual play through. It's best to follow the list below while breaking all boxes to be sure you collect them all.
1. The first effigy can be found after the first breakable barrier with the yellow marking on it. After destroying the barrier, turn to your left to find a barrel. On top of the barrel is the effigy along with some chemical fluid.
2. The second effigy is located near your first encounter with a gator. After the gator appears in front of you, turn left instead of following it straight. The effigy should be on the bank.
3. The third effigy is sitting on a sack next to the save station after breaking the barrier next to the crawling molded you had to opportunity to kill with the spear.
4. The fourth effigy is above the save station in the shack after your first mini boss fight with the swamp mutant.
5. After maneuvering your way through the gator ridden waters, you'll climb up yellow ladders onto the landing of the boat. Once going up the first set of stairs and fast the save station, there is another set of stairs leading down and a small path to your left. Take a left and you should see the fifth effigy.
6. After going below deck through the first breakable barrier, there are three enemies to be killed before breaking the second barrier. Once you find the crawling molded, there will be a box near it. In that box lies the six effigy. REMINDER: Some effigies are found in different boxes. Don't freak out if there isn't an effigy here. It could be in another box.
7. Break the second barrier and walk down the stairs (or jump off and stealth kill both molded). At the bottom, turn left, then right, then right again into a room. In that room, there is a box in the left corner. The seventh effigy is in that box. REMINDER: Some effigies are found in different boxes. Don't freak out if there isn't an effigy here. It could be in another box.
8. In the same room as the seventh effigy, there is a hatch that drops you down and leads you to the eighth effigy which also happens to be a champion effigy (1/4).
9. After the third breakable barrier, climb the ladder. Next to the synthesizer, there is metal shelving with a save station. Crouch to get the ninth effigy off of the bottom shelf.
10. After (or during) the second mini boss fight with the swamp mutant, break the boxes and find the tenth effigy. REMINDER: Some effigies are found in different boxes. Don't freak out if there isn't an effigy here. It could be in another box.
11. In Quarantine Area 1, there are a bunch of platforms you can use to make your way across the water to get to where you need to be. You can go left where there are two gators waiting or the right where there is one. Either way, once you climb up the ladder, follow the walkway to a small place with water and a fridge in the right corner. There will be a champion effigy here (2/4).
12. In Quarantine Area 2, following through the narrow passage above the water, you'll come to a room with a breakable barrier. Go through and drop down into the water. Climb up the ladder to the lone standing platform. There will be three spears and two boxes. The tenth effigy will be in one of the boxes. REMINDER: Some effigies are found in different boxes. Don't freak out if there isn't an effigy here. It could be in another box.
13. After the third breakable barrier, you'll see two spears to your right and a broken walkway in front of you. Drop down and continue up the walkway to the box in front of you. In that box is the thirteenth effigy. REMINDER: Some effigies are found in different boxes. Don't freak out if there isn't an effigy here. It could be in another box.
14. After getting the thirteenth effigy, continue around the walkway until you see a tree down below in the water. Drop down in the water to get the champion effigy out of the tree (3/4). Watch out for gators.
15. Continuing around the walkway. There will be a box to your right along with a molded. Break the box to get the fifteenth effigy.
16. After going through the last breakable barrier, go into the shack on your left. There will be the sixteenth effigy to the right of the save station.
17. After dropping down into the cemetery, go to the leftmost path. To the right, there should be a box. Break the box to get the seventeenth effigy.
18. After defeating the fat molded and breaking the barrier, the eighteenth effigy should be on the lamppost before the church.
19. While weaving your way through the Old house, you'll come across a fat molded near the exit. Instead of running for the door on your right, go straight and turn left to find the last champion effigy on the door (4/4).
20. After leaving the Old House and following the walkway, there will be an effigy on the wire to your right.