Snarky SIMON’s TV success has gone to his head as if he were CURIOUSITY landing on Mars – as IF!

The talent show mogul – who’s notorious for his fa­mously high opinion of himself – has come up with a hair-brained scheme to trim the backyard bushes at his $14 million London home into the shape of his head!

And the cost of his extraordinarily vain landscaping project hit a tree-mendous $63,000!

“Simon thought it would be really funny to shape his garden bushes like his head,” said an insider.

“Nobody really thought he was seri­ous when he first mentioned it, but he has a strange sense of humor, and the money to back it up.

“He was considering having topiary faces cut into the bushes, as well, but even he decided that was taking it too far.”

It’s not the first time Cowell – now in the midst of Season 2 auditions for “The X Factor” – has treated guests to likenesses of himself. At his star-studded 50th birthday party in his native England almost three years ago, the former “American Idol” judge splashed photos of himself every­where – even in the restrooms.

Simon, who also has another mansion in Beverly Hills, also had his lime­stone terrace redone because he thought it matched his complexion better.

Simon loves stunts like that and he knows he can grate on people’s nerves, once claim­ing he’d never get a knighthood because “the Queen said I was a dreadful man.”

And his lack of modesty is infamous – Simon says the one item he’d take to a desert island would be a mirror because otherwise he’d miss himself.