According to Plutarch Lycomedes, the King of Scyros, killed Theseus who had fled to his island in exile by pushing him off a cliff for he feared that Theseus would dethrone him.
In the case of Theseus of the Greek Legends, Theseus did die, but later life is rather enigmatic. After his son was killed by Poseidon's bull (or Dionsyus's bull in some stories) for supposedly raping Theseus's 2nd wife, his popularity declined. Some say that after his decline of popularity he left towards Lycomedes of the island of Skyros, who pushed Theseus off a cliff to his death. Overally, the theory that Theseus was pushed off a cliff is currently the only information regarding to Theseus's death.
Pushed him off his cliff, whereupon he was eaten by the giant sea-turtle waiting below.
skyros killed him by pushing him off a cliff when he was no longer popular in athens. Edit: Theseus had fled to the island of Skyros after being declined by his own people because the Athenian's were being told that Theseus was keeping them locked up in the city and took their powers away during Theseus' absence by a noble named, Menestheus. Theseus died by being pushed off the cliff on the island of Skyros, by the King of Skyros, Lycomedes in fear that Theseus would dethrone him.
Skyros killed him by pushing Theseus off a cliff when he was no longer popular among Athens.
Skyros didn't push Theseus off the cliff. Skyros is a monster, so he forces passerby to kneel to wash his feet. When the person kneels, he kicks him off the cliff into the sea, where his flesh-eating pet turtle is waiting to eat said person. Theseus, on his way to Athens, punished Skyros for his sin by doing exactly what Skyros did to others: Theseus threw Skyros off the cliff where the turtle ate his master. Then Theseus went on his merry way.
Skyros did not kill Theseus because Skyros is an island. He was killed on Skyros due to being shoved off a cliff by Lycomedes.
It brings about his loss of popularity in Athens; and his eventual wandering to Lycomedes of the island of Skyros who threw Theseus off a cliff.
Pirithous and Theseus
Jenine pushed him of a cliff
Lycomedes of the island of Skyros threw Theseus off a cliff after he had lost popularity in Athens. (due to what happened with Phaedra and Hippolytus)
Yes piggy was killed by one of the hunters named Roger who pushed a bolder off the cliff to where Piggy was standing which pushed piggy off of the cliff on to sharp rocks which killed him
You're probably referring to Sciron. Who appeared in the story of Theseus. He fed his victims to a Monstrous Turtle at the bottom of a cliff, Theseus used this same Turtle to kill Sciron.