I'll say it: You're mate has GREAT photo shopping skills if that is a King Brown. Quite simply they will NOT grow that length or anything near it. Based on the approximate length of the star pickets behind it, and allowing for distance error, I estimate the length of the snake, as pictured, would be 6 plus metres. The general maximum length of a King Brown is 3 metres, allowing for an extreme excess length of one third (unrealistic, I know) it would max out at 4 metres.
Result: photo shop, someone's pet snake placed there or cut and paste of a snake onto a smaller background. Sorry dude!
Glad you have a Jayco as well though!!