Melee◆ tail +6 (agile), Damage 1d4+1 bludgeoning plus 1d4 electricity plus Stunning Shock
Stunning Shock (incapacitation) A creature critically hit by the electric eel's tail must attempt a DC 17 Fortitude save.
Critical Success The creature is unaffected.
Success The creature is Stunned 1.
Failure The creature is Stunned 2.
Critical Failure The creature is Stunned 3.
Source: Pathfinder Monster Core
Running this fight? Add the electric eel to the initiative tracker: type its name and the AC, hit points and Perception for initiative fill in, and the book button shows this stat block mid-fight.