There's no end in sight for the ongoing love affair between Crocs, the maker of the often-mocked foam clog, and comfort-seeking consumers.

On Tuesday, Crocs reported that sales surged 64% in its first quarter, to $460 million. The company also raised its 2021 sales forecast, saying it now expects revenue for the year to increase between 40% and 50%, up from its previous guidance of a 20% to 25% increase.

Investors cheered the news, boosting Crocs shares up over 16% to $98.98 on the Nasdaq.

Crocs' bittersweet moment arrived in the midst of a global pandemic when the shoemaker logged its best sales ever in 2020. The clog, priced at $30 to $50 a pair and derided by many as ugly, became a go-to source of comfort for consumers who paired the shoe with everything from pajamas to fancy attire.

This past Sunday, musician Questlove was pictured wearing a pair of custom gold Crocs at the Oscars.

A couple of collaborations, too, have helped sell millennial and TikTok-loving Gen Z'ers on the clogs. The brand often teams up with a number of artists and brands, including Post Malone, Justin Bieber and fast-food chain KFC, on special edition collections. Its glow-in-the-dark collaboration with Latin trap artist Bad Bunny quickly sold out after its September launch last year.

New this year was a collaboration with French EDM artist Vladimir Cauchemar that featured his signature SkullMask. In March, the company launched a second global collaboration with Justin Bieber.

On Tuesday, a limited-edition $50 light-up bright red Lightning McQueen adult clogs modeled after the Disney/Pixar character from "Cars" sold out under an hour after it was released for online purchase.

"Some [of our collaborations] are designed to attract new customers and to be able to market to them in the future," Crocs CEO Andrew Rees told analysts during an earnings call on Tuesday. "And some of them are designed to be kind of interesting and buzzworthy. In 2021, we will do more international collaborations."

text by Parija Kavilanz, CNN Business