According to ACCRA24.COM, the guy was sucking out the bowel or whatever the snake has digest, that is break down (food) in the alimentary canal into substances that can be absorbed and used by the body.
So the Snake Sucker intake and give life to the dead Snake.
WATCH FULL VIDEO OF SNAKE SUCKER BELOW:
Any vet clinic will have the proper tools for intubation, ventilation and monitoring the oxygenation level of an unconscious patient. Drugs that may be used in the resuscitating of snake patients after anesthesia include specific reversal agents, Dopram as a respiratory stimulant and epinephrine as a general stimulant. But in the laboratory or zoo environment, special drugs or equipment like a ventilator may not always be available to help a snake recover or to resuscitate a non breathing animal in an emergency situation.
This is a safe and reasonably effective method for keeping an unconscious or semi conscious, non breathing snake at least partially oxygenated. Grasp the snake firmly with its head in a standard Midwest snake tube and create a partial seal around the tube and the snake's body as shown using a latex or rubber glove, plastic wrap, a sandwich bag, a garbage bag or anything else handy that is flexible and not gas permeable. The plastic should be held firmly against the tube and around the snake's body, but not so tightly that the snake's airway is closed off.
Making sure the snake's head is restrained on the end of the tube nearest your hand, press the other end of the tube over your mouth and blow gently. Only make a full seal on one end of the tube, either with your mouth or with your hand. The other end should allow some air to flow so that you don't create too much air pressure. You can tighten both seals if you don't have enough air pressure to force air into the snake's lungs. If the snake's glottis is open, you should see the snake's body expand slightly in response to your gentle puff.
Do not blow too hard or too long. Do not overinflate the snake. To give a full breath to the three meter long, two kilogram king cobra shown in the photo, you should be blowing with barely enough force to move a Ping-Pong ball slowly across a smooth table. Stop immediately if you feel pressure or resistance to your puffing, or loosen the seal. To give a breath to a smaller snake, blow even more softly.