We all have a Bull Mastiff by the name of Butkus to thank for Sylvester Stallone's rise to stardom.

Yes, you read that correctly.

This content is imported from Instagram. You may be able to find the same content in another format, or you may be able to find more information, at their web site.

Stallone took to Instagram to gush about the "modern day miracle" that is Butkus.

In his twenties, Stallone invested in a small pup, and since he was flat broke they ended up spending a whole lot of time together and that's when he learnt the craft of screenwriting.

SEE ALSO: Sylvester Stallone Has Shared A Treasure Trove Of Rocky Photos

And since Stallone never went out, he began to rely on Butkus for companionship. The actor even joked how it was in fact Butkus' idea to write Rocky.

This content is imported from Instagram. You may be able to find the same content in another format, or you may be able to find more information, at their web site.

Their relationship took a rocky turn when Stallone had to sell him for $40 because he had gotten to the stage where he couldn't even afford dog food.

However, the story has a happy, yet somewhat grippingly expensive end, as he managed to buy Butkus back for $15,000 when the screenplay for Rocky sold.

This content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. You may be able to find more information about this and similar content at piano.io