Washed Away - Old Lestallum
First Available: Chapter 3
Other Requirements: Complete A Backwoods Burial
Location: Old Lestallum
Rewards: 1,800 EXP & 10 Phoenix Down
You're able to pick up this quest immediately after completing the A Backwoods Burial quest given by Dave. Much like for the previous quest, you'll want to head over to the owner of the Diner and speak to him to narrow down the location. Hop in the Regalia then drive on over to the spot on your map.
This Dog Tag can be a little bit annoying to locate, it's found on the rocks and in the bushes, as shown in my screenshot below.