Microsoft bought GitHub on Monday and released a photo of CEO Satya Nadella sitting in front of ... wait, what IS that thing?

For the uninitiated, that giant statue of a feline-cephalopod hybrid is Octocat, GitHub's logo. Octocat isn't just a logo or a mascot — it's an inside joke shared with the 28 million software developers who use the service to share code with one another.

It's a trademark registered to GitHub, but the platform's members are constantly creating Octocat memes or pictures of Octocat posing as various people. GitHub has a repository of more than 100 member-created images of Octocat, including the mascot dressed as Santa Claus, a member of Daft Punk, and Homer Simpson.

GitHub has several websites devoted to Octocat. The company claims that Octocat is "quick and limber" and struggles with gravity and balance while on land.

Related: Microsoft buys coding platform GitHub for $7.5 billion

You can buy an Octocat figurine for $15. GitHub said it struggled designing the figurine in 2014, because Octocat appears in different drawings as a quadruped, a biped and a pentaped — but never an octoped. Making an eight-tentacled Octocat felt "inauthentic," so it settled on five, the company says on the figurine's website.

"Part of the beauty of the Octocat is her paradoxical nature," GitHub says.

Octocat actually began as "Octopuss," an image created for iStockphoto.com by illustrator Simon Oxley. Incidentally, he is also the creator of the original Twitter bird.