When I was in Thailand some years ago, training with the Thai Marines we killed several cobras as part some survival training. They were killed by beheading, then the about 4" of tail was cut off to allow blood to flow freely out, where it could be drank straight from the serpent's neck.

They believed the cobra's blood increased a man's virility. Whether it did that or not I don't know. Anyhow, the taste is not terribly disagreeable, but my concern would be with salt in the blood. As Sue pointed out, some water to dilute it might be necessary.