Being unpredictable and prepared will go a long way for your Jiu-Jitsu. That is: if you have the skills and you can set them up in unpredictable, sneaky ways… You’ll be able to submit your opponents with relative ease!
Therefore, here’s arguable the sneakiest attack in Brazilian Jiu-Jitsu – the Ezekiel Choke from Closed Guard!

It’s actually much more simple to set up than you may think it is. Coach Tom from The Grappling Academy demonstrates how to do it.

EZEKIEL CHOKE FROM CLOSED GUARD 

So, how do you go about setting up the Ezekiel Choke from Closed Guard? Coach Tom explains that the best opportunity for it may lay in a situation when you’re nearing the end of a roll or a competition match; when there’s little possibility that you’re going to be able to escape the other person’s Closed Guard and therefore win the match.
Additionally, if the other athlete grabs your collars and pulls you towards themselves… You have a ripe opportunity to choke ’em out!

Slide your hand underneath their neck in a powerful Crossface manner; all the while you stand up on your legs, shifting your bodyweight forward. This way, you’re going to form a sort of a tripod, and should be really stable.
Then, slide the fingers of the Crossface arm into the opposite arm’s sleeve. From there, shoot that opposite hand across the opponent’s neck and initiate the Ezekiel Choke.
Just beware not to extend your hands too much while applying it, as an Armbar awaits for you in that case. Therefore, keep your head close to their head!

All of the details are explained here: