Dave is an adorably bland hunter you rescue during the quest "Hunter Becomes Hunted" early on in the game, after which he'll pop up at various outposts offering you quests. He may be a hunter, but all your interactions with him don't exactly give him an air of authority... or competence. Still, he deals with the inevitable consequence of the hunting profession - not all hunters make it, and those who don't leave behind their Dog Tags. The tasks he give you revolve around gathering these trinkets, so the dead can be properly honored. All in all his quests are pretty simple: go to the indicated area, kill whatever beasts lurk nearby (presumably those that killed the missing hunter) and claim the Dog Tag. The rewards, aside from a paltry amount of experience, typically include a bundle of restorative items.
|Longwythe Rest Area||Give Cindy's package the proprietor of the Three Z's Motel - Longwyth during the quest "The Errand Prince"||500 XP, Hi-Potion x10|
After your first foray into the main story quests of the game, Cindy will ask you to deliver a package for her. On your way to Galdin Quay, you will stop by Longwythe Rest Area to drop it off and once you finish up there, you can start this sidequest by speaking with the NPC in front of the motel. You are handed a sealed envelope to bring to the head hunter, who just happens to be Dave. He can be found across the street from the motel, so bring him the sealed envelope.
Dave wants you to track down some dog tags from missing hunters, but the first set comes without a location. So, visit the tipster and choose the info option to get a quest marker on your map. Once you arrive there, inspect the campfire to get a clue as to the location of the dog tag, although you notice something moving nearby. Go to investigate the new waypoint to find some Sabertusks, so take them down and look nearby for the dog tags. When they're in your possession, bring them back to Dave to finish the sidequest
Dust to Dust
|Prairie Outpost||Finish "Gone Hunting"||600 XP, Mega-Potion x5|
For his second quest, Dave has moved to the Prairie Outpost, which is located to the northwest of Hammerhead. As before, he wants you to track down some dog tags, with this one being located to the east of the Norduscaen Blockade parking spot that's a little bit south of the outpost. When you get to the search location, you will find some Anaks, Anak Calves and Daggerquills hanging around. Once the coast is clear, look next to the car that's near the tree for the dog tag. Bring it back to Dave to finish the quest.
Final Resting Plains
|Coernix Station - Alstor||Finish "Dust to Dust", Complete Chapter 2||800 XP, Elixir x10|
Coernix Station - Alstor is the first stop you get to in Chapter 3, whenever you first gain access to the Duscae region. From the Coernix Station - Alstor, make your way south-west along the highway until you reach the Rydielle Ley Parking Spot. From here head south until you find a shack, around which are a herd of Garula. Kill them, then search along the western edge of the shack to find the Rusted Dog Tag.
A Rocky End
|Cauthess Rest Area||Finish "Final Resting Plains"||1,000 XP, Hi-Elixir x10|
South of the Disc of Cauthess you'll find the Cauthess Rest Area outpost, where Dave will be waiting to give you another quest, should have you completed all his previous ones. Once you have this mission you'll have to drive to the Taelpar Rest Area, then make your way along the highway (through a tunnel) north of the rest area until you reach a fork in the road south of the Secullum Pass Parking Spot. Leave the Regalia and make your way south-west into the wilderness where you'll find a pack of Voretooths. Kill them and search near some boulders along the souther-western edge of the search area to find the Scorched Dog Tag.
Swallowed by Shadows
|Taelpar Rest Area||Finish "A Rocky End"||1,200 EXP, Hi-Elixir x10|
This quest begins near where the last quest's objective lay: the Taelpar Rest Area. Talk to Dave here to get the quest, then drive back north-east until the highway turns north. If you go north you'll be back at the Cauthess Rest Area. There is, however, a small dirt road continuing to the east, south of The Archaean's Mirror Fishing Spot. Disembark on this road and head uphill to the south to find a logging shelter, around which are a swarm Hundlegs. Kill them and search the shelter to find a Twisted Dog Tag on the ground between some cut logs and a table.
A Backwoods Burial
|Old Lestallum||Finish "Swallowed by Shadows"||1,500 EXP, Phoenix Down x10|
North-west of the Taelpar Rest Area outpost is the Old Lestallum outpost, near which you'll find your old buddy, Dave, who naturally has another job for you. Drive the Regalia along the road west from Old Lestallum, then at the first fork turn north until you reach a second fork (this second fork is just south-west of the Rachsia Bridge Fishing Spot). At this second fork turn east and head up the road a bit until you find a gap in the guard rail to the north. Leave the Regalia and head through this gap and up the trail beyond it until you reach a barn (the building the north-west, not the one to the east), outside of which you'll find the Scratched Dog Tag. Before you can grab it, however, you'll be pestered by a pack of Havocfangs - advanced Voretooth-type monsters that can cause Confusion.
|Old Lestallum||Finish "A Backwoods Burial"||1,800 EXP, Phoenix Down x10|
After turning in the Scratched Dog Tag you can talk to Dave again immediately to get this quest. Travel to the Wennath Reiverhead Parking Spot far to the north and park at it, then head south along the highway until you find some stairs leading down to the wilderness around the Wennath River. When you reach the search area near the river, kill the Sahagin and Seadevils lurking around (and any of the imperials that drop in on you - this area is a notoriously popular dropzone for them) then search along the northern end of the search area, on a rocky shelf obscured by some large bushes. The Crushed Dog Tag can be found hidden amongst some foliage.
Mountains of Misfortune
|Meldacio Hunter HQ||Finish "Washed Away"||2,000 EXP, Megalixir x5|
You can pick up this quest after completing "Washed Away" by traveling to the Meldacio Hunter HQ and talking to Dave. Unfortunately, the quest takes place in the Vesperpool area, so you'll need to wait until Chapter 6 (ideally Chapter 7, for party composition purposes) to complete it. When you have access to the area, make your way to the search area along the north-eastern reaches of The Vesperpool (north-east of the Steyliff Grove dungeon) to find some ruins, now prowled by a Cockatrice. Kill it and search near the ruins it was guarding to find the Polished Dog Tag.
The Witch of the Woods
|Verinas Mart - Ravatogh, get intel from the owner of Erupto Eats||Finish "Mountains of Misfortune"||2,500 EXP, Mega Phoenix x5|
When you get to Verinas Mart - Ravatogh, you might have a hard time finding Dave, as he isn't really there. Instead, speak with the proprietor of the Erupto Eats stall to gain intel on Dave's whereabouts, which point you south to Malmalam Thicket. Head over Telghey Haven Campground, and from there head south, then east to find the trail leading to Malmalam Thicket. On this trail you'll find Dave (although not where the map marker indicates - he'll be futher long the trail, contemplating a sign).
After talking to Dave you'll need to follow the trail to the north and when you find a break in the rocks to the south-west veer off the trail in that direction to find another, unmarked trail that runs south-west and south, eventually ending at the "House of Hexes" Talk to the "witch" - Kimya - outside of her house to learn about the hunter, after which you'll need to make your way through Malmalam Thicket, including its boss, a Bandersnatch.
Once the Bandersnatch is dead, make your way to the Tomb of the Pious and from its entrance turn west to find the Sullied Dog Tag merrily glowing away near a boulder and a tree. Leave Malmalam Thicket and return to Kimya, who will pass on a generic message for you to deliver to Dave, who will be waiting for you at Meldacio Hunter HQ, in his customary spot. Give him the Sullied Dog Tag, tell him what the witch told you (more or less) and he'll have a little heart-to-heart with you. More importantly, this ends Dave's questline.