Probably the best example of a cat who's made the most of internet fame, Grumpy Cat's first film came out just before Christmas and she has a representative - Ben Lashes (no, really, that's his name) who calls himself an 'internet meme talent manager'.

Grumpy Cat, real name Tardar Sauce, isn't actually grumpy but appears like that because of a form of feline dwarfism. She has over 7 million followers on Facebook and thousands more on YouTube, Instagram and Twitter.

Owned by a Facebook employee in San Francisco, Boo's fame on the internet spread wildly after someone called Khloe Kardashian linked to his page in a tweet, saying he was the "cutest dog on the planet", and a singer called Kesha said he was her new boyfriend.

Boo now has a following of more than 16 million people and merchandise including a picture book and stuffed animals. He is also the Official Pet Liaison for Virgin America, whatever that means!

Born as the runt of a litter, Lil Bub was rescued by owner Mike Bridavsky in rural Indiana, USA. She is a tiny tabby with bulging eyes and a tongue that stays out most of the time because of a short lower jaw and lack of teeth.

This cute look made her famous first on Tumblr before spreading to other social media sites. She now has her own talk show on the web, let alone the books, toys and mugs etc.

Many pets become famous on social media because of their owners and Maggie May is no exception. She is one of Andy Murray's two border terriers and is pretty amusing on Twitter, for a dog. There are (unproven) rumours that her Twitter account is actually run by Andy's fiancée, Kim Sears.

Another famous person's pet, Graham relies heavily on owner Ed Sheeran's following but is now developing a career on his own, having had a stint as an Agony Uncle at Sugarscope.com, a young person's 'lifestyle' website.

Like Lil Bub, Marnie the dog was a rescue animal and suffered during her upbringing, having an uncontrollable long tongue and being blind in one eye. That hasn't stopped her from becoming the third most followed dog on the internet with nearly a million people.

She enjoys dressing up and just to confuse us, was photographed with Ed Sheeran at the Grammys a few weeks ago. We assume she got Graham the Kitten's permission?

The Prof is a black and white cat belonging to Canadian electronic musician Deadmau5, or if you believe the Professor's Facebook page: "deadmau5 is just my pet". Listing interests as "mice, food, bass, socks" the Professor has already featured in adverts for Sonos, the wireless music system, with his pet/owner.

This is just the tip of the iceberg, of course. Strangely, although the internet seems to feature far more cats than dogs, a study released about eighteen months ago found that dogs were more likely to have their own social media presence.

Perhaps your pet is on social media too - or if not, have you considered creating a page for them? You never know where it could lead.

Do you have a favourite cat or dog personality on social media? Why not email and let us know about them - perhaps we can have a follow-up featuring your favourites.