Remember the era. I think you mean New Coke
I'm going to be running an 80's style McDonald's campaign.
Any races that appeared in McDonald's commercials are playable races. Humans - obviously. You can also play as an ooze (Grimace), an aarokocra (Birdie), goblins (Fry Guys and Fry Gals), kobolds (the McNugget buddies) or a variant human (Mayor McCheese and Officer Big Mac).
There are class and alignment restrictions:
Rogues are required to wear domino masks, wide-brimmed black hats, and a B&W striped matching shirt and trousers, and are always Chaotic. You may however play Chaotic Evil, you automatically speak Rubblese, and all attempts to burgle hamburgers are rolled with advantage. Similarly, in this campaign, goblins cannot be lawful because they always try to steal fries.
Oozes are all evil. I am adamant about this because Grimace was, as originally written, "the Evil Grimace." DEX cannot ever go above 5 because you have stupid stumpy arms. Also, you are vulnerable to milkshakes.
Aarokocra in this world all have DEX below 9 and, while I permit flying, any attempt to land requires a DC15 saving throw against fall damage.
Kobolds do get pack tactics but only if they are with at least 5 other kobolds because they come in 6 piece at a minimum (I will allow a lower 4, but only with a small goblin present (Fry Guy)).
If you choose variant human, I will require your character to be a Lawful alignment and have a hamburger for a head. There are no feats but you can choose a build from any of the 9,382 brown 2e splatbooks.
I will also let one player play an illithid, but the illithid has a 1 CHA and must consume at least 10 cans of New Coke per day or die. Also, its name is MAC.
All non-spell casters start with styofoam armor (AC 10, confers resistance to attacks from plant-based creatures and spells).
The basic plot is that the party is tasked with slaying the bloody-thirsty tyrant Mac Tonight. He can only be slain with a McDLT and, even if you procure the McDLT, you need to keep the hot side hot and the cold side cold until assembling it to kill Mac Tonight.