Marvel's mouthy mercenary Deadpool is no stranger to breaking records.

The latest film in his franchise, 'Deadpool & Wolverine', has just taken the crown of being the highest grossing R rated film of all time.

'Deadpool & Wolverine' opens to 'spectacular' $205 million

'Deadpool & Wolverine' sets new records in N.America theaters

Now, uncolored penciled cover artwork featuring Deadpool's first appearance in the comics is up for sale at Heritage Auctions with a hefty $7.5 million price tag. If it sells at that price, it will be the most valuable comic book art ever sold.

The artwork was created by writer/artist Rob Liefeld, for New Mutants #98, which was released in February 1991 when Liefeld was just 23 years old.

Liefeld does not own the artwork. He sold it to a collector 25 years ago, although he is thrilled that the character he created is doing so well financially.

"I just keep smiling," said Liefeld about the auction.

When New Mutants #98 was released in 1991, it cost just one dollar. Now the original editions have become one of the most sought-after comics for collectors, with issues selling from between $350 to $55,000 on eBay.

But Liefeld has no regrets about giving up his original art.

"Selling artwork was part of the income stream back then," he told Reuters. "I sold this 25 years ago. I have zero regrets."

Liefeld created Deadpool as a combination between Spider-Man and G.I. Joe. Immediately after his first appearance, Marvel Comics was flooded with fan mail.

"Marvel contacted me and said, this is the most fan mail we've had on a new character in 15 years," said Liefeld. "They were flooded with letters, fan letters, which they sent me. And the box that that mail arrived in.... I thought I was getting a washer and dryer," he joked.

But creating a character that makes jokes about everything has its drawbacks. In the films, Liefeld has been ridiculed for the way he draws feet in the comic books. Towards the end of 'Deadpool & Wolverine', both the leads fight a corps of Deadpools in front of a store named 'Liefeld: Just Feet'.

"I love it!", said Liefeld, adding "Ryan Reynolds said, Rob, we have done quite a tribute to you."

Although Deadpool has put Liefeld in the annals of comic book history, he still doesn't like him that much.

"If Deadpool existed, I'm not sure we'd get along. You know, he's an asshole," he said, adding "If you paid him money to shoot me and I paid him more to shoot you, he'd shoot you. That's the kind of compromised person he is."

The current record holder in comic book auctions is a copy of Action Comics #1, which features the first appearance of Superman and sold for $6 million earlier in the year, also at Heritage Auctions.

If the Deadpool artwork sells for $7.5 million, the character could be seen as one of the most important comic book characters of all time.

"Deadpool is here to stay," said Liefeld.

"He is, like I said, one of the pillars of the next generation and I'm just so excited that that that this artwork has come out of the collection and is being seen and and the appreciation is there. But again, it represents an era that is very special to, I think, the fans, quite frankly, who are carrying the business right now, the fans who are carrying the business were the teenagers that bought New Mutants #98," he added.

Bidding on the artwork begins Wednesday (August 7), with the auction closing on August 14.