The Twisker Sock
The "Twisker Sock" or "Twisker Punch" is Popeye's most devastating fighting technique, and he has been seen to use it in comics, film and animation. It is not a common sight, though: as he explained to Bluto during their first encounter, Popeye's ultimate attack is potentially lethal, so the sailor would only use it as a last resort.

The attack consists of Popeye twisting his forearm muscle until it is completely wrapped unto itself, then striking at his opponent. This not only grants the punch increased force but may also cause the victim to spin vertically as Popeye's forearm becomes unwrapped.