writhing

(verb) to move in a twisting or contorted motion, (especially when struggling). Synonyms: writhe, wrestle, wriggle, worm, squirm, twist. Examples: "The prisoner writhed in discomfort." "The child tried to wriggle free from his aunt's embrace."

(adj) moving in a twisting or snake-like or wormlike fashion. Synonyms: wiggly, wriggling, wriggly. Example: "Wiggly worms."