well maybe just for fun,and for people like you to react,im sure it got your attention hehehehe.
well for me my vote is maybe for the piranha,coz it has a sharp teeth made for slashing flesh,a piranha will surely take a bite once a while until the snake get its fins nippped and be eaten specially at night where piranhas have a clear site which is a major dissadvantage for the snakehead which is almost blind at night
A Giant Snakehead would take on a Piranha of the same size anytime, small fish are taken in a gulp, bigger fish would have half of its body gone before taking the other half or leaving it as its mark. A Giant Snakehead can handle itself alone, but a Piranha is only deadly when it's in packs. It takes a pack hunter of Piranhas to murder a man, but it only takes a single huge adult Giant Snakehead to do the job.
For a predator that breaks tank glass, attacks its owner, cleans tankmates, cuts wires, breaks lures and even up to killing swimmers, a Giant Snakehead is clearly a living torpedo in the water. Below are pictures of attacked Piranhas, a young juvenile ruling a Piranha tank as said by the owner himself as well as pictures of their teeth~!
i was asked at my fantasy football draft, "who would win in a fight, a bluefish (ocean) or a pirhana?" my response was they were from 2 different types of water and it was stupid. his response was, "well what if it were in brackish water?" by the way, he didnt even make the playoffs and he drafted daunte culpepper in the 3rd round... he's slow)