Here's the Sicilian Defense: Closed Variation, Chameleon Variation. It may look strange, as both the light-squared bishop and queen are shut in, and castling might seem some way off. Transpositions back to more common lines are easily achieved with d4, but being an unusual reply to the sicilian things can quickly go out-of-book.

The perks are that

1)   f4 is preserved. 

2)   Every so often black with reply with e5. This is the second most common reply in chess.com games, and the main reason I like the Chameleon. You lose control of a few important squares, but get to post a very strong piece on d5. The three games below all follow this line. I've included one by Fischer, to give the opening some cred.

 

 

 

 

 

 

 

 

 

 

 

 

 

This looks like a lot of fun!  I'm going to have to give this a whirl.

I think I will give it a try also! But please don't tell anybody!

good combination!

Another thing is its flexibility: White can opt for a Closed with g3 and Bg2 or open it if black does not play e5