Meet CosMc, the obscure alien McDonald's mascot behind its new restaurant spinoff chain

• McDonald's announced Thursday that it's opening up a spinoff chain called CosMc's.
• CosMc is an orange alien and obscure McDonaldland character from the late 80s.
• Mcdonald's has been capitalizing on nostalgic, forgotten mascots — with Grimace taking the internet by storm.

On the heels of its wildly successful Grimace-themed marketing blitz, McDonald's is digging back into its back catalogue of McDonaldland characters for a new chain of spinoff restaurants called CosMc's.

McDonald's CEO Chris Kempczinski told investors on Thursday that the chain would begin opening in early 2024, but said he'll reveal more details about what it'll actually look like at the end of this year.

But while Grimace is fairly well known — he was the punch-line of a joke in an Avengers movie, after all — CosMc is definitely less popular.

So what exactly is CosMc.

The lesser-known vintage McDonaldland character is an alien who first appeared in a commercial called "The Story of CosMc" in 1987.

In the commercial, a strange silver object rockets down to McDonaldland from outer space. Ronald McDonald, Grimace, and The Professor notice the vessel and Ronald McDonald knocks on it.

Out pops CosMc — an orange alien with six arms, a blob-like head, and sneaker-wearing feet. It's not clear if CosMc is wearing the spacecraft like a suit, or if it's part of his body like a turtle's shell.

"Hi-ho Earth people, CosMc here! I popped in from outer space on a trade mission," CosMc announces. He then proceeds to "trade" weird alien-looking objects, like a colorful lamp and a duck hat, for Ronald McDonald's skateboard and Grimace's headphones.

Then, CosMc snags the group's picnic basket of cheeseburgers, fries, and shakes, and zooms off, handing out weird-looking flowers in exchange.

But, smart-thinking Ronald McDonald uses his McMagnet to pull CosMc back, and the group decides to eat lunch together.

"Deliciously awesome!"CosMc exclaims. "I've got to tell my people about McDonald's cheeseburgers. Later, dudes!"

In 1988, CosMc appears in another commercial, where CosMc takes Ronald McDonald on a tour through outer space. CosMc shows him a "fly-through" McDonald's restaurant that CosMc seems to have opened up on the moon.

And again in 1989, CosMc and Ronald McDonald have another adventure where they agree to meet up, but CosMc jets down to Earth and McDonald flies to space on a star. They eventually share cheeseburgers in outer space while laughing about the mix-up.

One of CosMc's final public appearances happened in 1992 in the Nintendo video game, M.C. Kids, where CosMc leads an "earth dude" to Hamburglar's hiding place.

But aside from those cameos and some small appearances on McDonald's merchandise, CosMc has mostly been absent from the McDonaldland universe — until now.