With a Metal Worker in play, all your creatures in your hand are artifacts now
Then these surveil 1 on arrival to the battlefield, so they can give you card draw security, and then also send it to the graveyard if you don't immediately need it, or just want reanimation, flashback or delirium for later use
Ideal for storing a 100-card single-sleeved Magic: the Gathering Commander deck
You can't cheat him into play from your hand with Kaalia, and you can't find Clive in your deck with Terra: They care about enchantments, and Clive's front face isnt an enchantment
Finally, Kazandu Mammoth is a fairly on-curve creature that works really well with green ramp spells that tutor extra lands onto the battlefield
Only one card has been printed of The One Ring (Serialized 001 of 001), and this card can only be found in one English-Language Collector Booster