Over 58 million Wally books have been sold in 38 countries worldwide and translated into 30 different languages and he's even found his fame on Facebook, with four million fans!
Given his chosen attire of red and white hooped jumper and bobble hat, some of you may have already had your suspicions that Wally has a bit of a soft spot for Gloucester Rugby.
And, it's now been confirmed, Wally is a Gloucester Rugby fan and wanted to involve the crowd at Kingsholm this weekend in his celebrations!
The EDF Energy London Eye and the Empire State Building are both turning red and white for the day, and a number of fashion brands and celebrities have also 'shown their stripes' with special limited edition products so keep your eyes peeled.
Look out for special Wally masks which will be available around the stadium on Saturday and join in the fun using the hashtag #showyourstripes or becoming a Wally fan on Facebook (facebook.com/whereswally).