Final Fantasy XV Sting Your Praises is the third and the final side-quest you can complete by talking to the arms vendor in Lestallum.
Sting Your Praises is similar to the two previous side-quests you have completed for the said vendor, meaning that you will be asked to bring back a specific material that is dropped by a beast.
When both of these quests are completed, talk to the arms vendor and he will send you to another area to hunt some Saphyrtails.
Objective: Slay Saphyrtails
From your current location, travel back to your car and then drive to Cleigne area, following the quest marker on your map.
If you wish to move faster, you can simply fast-travel to the Ravatoghan Trail Parking Spot.
Next, mount your Chocobo and ride to the area north of the road leading to The Rock of Ravatogh dungeon.
When you get close to the marker you should see a pack of Saphyrtails that look similar to scorpions.
The Saphyrtails in Final Fantasy XV are weak against all swords (one-handed and two-handed) as well as Lightning spells, but they are resilient against Ice and Light spells.
Use the recommended weapons when fighting them and block as many attacks as you can.
The drop rate of a Scorpion Stinger is 30%, so you won’t encounter any difficulties in getting the material required by the arms merchant.
Objective: Deliver the Scorpion Stingers to the Arms Merchant
When you have at least one Scorpion Stinger, head back to your car, then fast-travel to Lestallum.
Talk to the arms merchant to complete the quest along with his quest-line. In exchange, the arms vendor will reduce the prices of all items he is selling.
Sting Your Praises Quest Info
Description: “The arms merchant will compensate Noctis for bringing him the stingers of the venomous insects known as saphyrtails.”
Reward: Discount to all items sold by this vendor
Post Quest Suggestion
Complete The Perfect Landscape side-quest.