Despite only launching last year, the Pip range is already being stocked in over 500 outlets in the UK, including Fenwicks and John Lewis.
Over 100,000 cards have been sold since launch and the range is also available across several European countries, Australia/NZ, Japan and Canada.
Over the Moon MD Karen Bendy, said: “The cards have really struck a chord with people and this made us realise that Pip has enormous potential across any number of sectors - we have appointed Kirsty to help realise that.
“It’s great to have someone with her level of expertise and experience on board and I’m looking forward to seeing Pip taken to the next level.”
Guthrie added: “I am delighted to be representing Pip. This striking character caught my eye immediately and when I heard about how successful the Pip card range is, I imagined the endless opportunities of Pip translating onto all different types of product platforms.
“Over the Moon are a very talented company and we will implement a multi -platform licensing programme to include licensed product, publishing and interactive. This cat has got a lot of charm and humour and will appeal to adults as well as tweens and children of all ages.”