Artlist Collection's The Cat and The Pig will both be listed on print-on-demand greeting card website, Moonpig.com.
The new relationship covers the UK, Ireland and Australia, with a range of Valentine's Day cards featuring The Pig already available on Moonpig.com and Moonpig.com.au.
The designs are also being featured in Moonpig's advertising campaign on the London Underground.
New designs for The Pig and The Cat will also be available soon.
"Like The Dog, The Pig and The Cat have significant visual appeal and are perfect for greeting cards, so it's fantastic to have Moonpig - a very dynamic company - on board," said Sandra Vauthier-Cellier, MD at 4Kids. "This latest agreement adds another category to the impressive list of licensees for the whole Artlist Collection franchise and perfectly illustrates the flexibility of these brands."