Fallout – (GRA) Overkill * Challenge: What qualifies as an “Animal” for this challenge

Ammo Boxes are essentially a source of cheap bulk ammo. If you'll notice, each one mentions that it's a particular kind of ammunition. If you buy an Ammo Box, drop it on the ground, and then interact with it (Not sure if there's a smoother way to do this, but it's how I figured it out), you'll get a whole lot of ammunition. For reference, the box of Bulk Energy Cells sold by Chet in Goodsprings contains 100 cells. Unfortunately, being Bulk ammo, each one does 85% of normal damage. Good enough for cash-strapped Couriers, but far from ideal.

Also, be sure to distinguish Ammo Boxes from Ammo Cases - the latter are weightless, and are used in crafting for the production of new and specialty ammo.

I've made this community wiki so that more people can edit it and we can simply have one definitive answer. In doing so, I've also incorporated answers not only from what I've found via gameplay and The Vault, but also the other answers which are on this question as well.

• Sarah Weintraub: Various Vault Jumpsuits, but not armored ones nor utility suits.
• Festus: Sunset Sarsaparilla Star Bottle Caps (sort of -- with 50, he, sort of, gives you the "reward" of hearing the history of Sunset Sarsaparilla and a quest for the "real" reward.)
• Jane (Lucky 38): Snow Globes (the spiritual successors of Bobbleheads from Fallout 3, but do not grant any bonuses)
• Raquel (Boomers): Missiles (thank you Brian Schkerke)
• Jack (Boomers): Scrap Metal (thank you Douglas Leeder)
• Julie Farkas: Fixer, RadAway, Med-X
• Decanus Severus: NCR Dog Tags
• Quartermaster Mayes: NCR Dog Tags
• Private Sexton: Legion Ears
• Lindsay (Boomers): Mr. Cuddles (unique item)
• Ruby Nash: Radscorpion poison glands (traded for Ruby's Casserole)
• Isaac: 100 scrap metal, tin cans, bent tin cans, pots, coffee pots, metal cooking pans, metal cooking pots and/or irons
• Jas Wilkins: 1 deathclaw egg
• Children near Nellis Hangars: Rocket Souvenirs (though you only get Boomer fame, no caps nor other rewards)
• First Sergeant Astor: Irradiated NCR Dog Tags