Each of The Entertainer's stores will have one winner, who will receive a bundle of five exclusive Webkinz pets.
This follows a recent half-price promotion at the stores, also designed to promote the Webkinz line.
Paul Jackson, managing director of The In Thing, said: “As normal, The Entertainer are ‘quick off the blocks’ spotting a new craze.
"This competition is the first of many exciting promotional activities planned for Webkinz throughout the summer months to back up our substantial TV campaign."
Stuart Grant, buying director, The Entertainer, added: “We are excited to run this promotion for Webkinz in our stores.
"We’re enjoying the initial success of the new Webkinz to date – and it’s clear to see why. They’re an innovative and fun children’s collectable."
Each Webkinz plush pet comes with a unique secret code which allows kids to adopt their pet via the fun, safe and educational Webkinz World.
The online platform is a virtual world where users roam, explore and watch their pet transform from a soft plush toy to an online pet.