7-Eleven is marking its 98th birthday on July 11 with a nationwide celebration of its most iconic frozen treat.

Customers can enjoy a free small Slurpee drink at participating 7-Eleven, Speedway and Stripes stores nationwide.

“This Slurpee Day, we’re mixing things up with new flavors, our celebratory swag and even a twist designed to mark tastebuds in the coolest way possible,” Marissa Jarratt, executive vice president and chief marketing and sustainability officer at 7-Eleven, Inc., said in a statement.

This year, the chain is introducing “tongue-toos,” a kind of temporary tongue tattoos that appear after sipping a Slurpee.

The tattoos, available in blue, green, red, and purple, feature the Slurpee “S” logo and will be handed out to loyalty members at select 7-Eleven and Speedway stores in cities including Los Angeles, New York, Dallas, Detroit, and Chicago.

7-Eleven is also releasing limited-edition birthday-themed merchandise online via its 7Collection capsule.

Founded in 1927, 7-Eleven is the largest convenience retailer in the world, with more than 13,000 stores across the U.S. and Canada.