The Collaborative International Dictionary of English v.0.48:

Strangler \Stran"gler\, n.
   One who, or that which, strangles. "The very strangler of
   their amity." --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

strangler
    n 1: an epiphytic vine or tree whose aerial roots extend down
         the trunk of a supporting tree and coalesce around it
         eventually strangling the tree [syn: strangler,
         strangler tree]
    2: someone who kills by strangling [syn: garroter,
       garrotter, strangler, throttler, choker]

Moby Thesaurus II by Grady Ward, 1.0:

50 Moby Thesaurus words for "strangler":
   Cain, Jack Ketch, apache, assassin, assassinator, beheader,
   bloodletter, bloodshedder, bravo, burker, butcher, button man,
   cannibal, chastizer, cutthroat, deathsman, desperado, discipliner,
   electrocutioner, eradicator, executioner, exterminator, garroter,
   gorilla, gun, gunman, gunsel, hangman, hatchet man, head-hunter,
   headsman, hit man, homicidal maniac, homicide, killer, man-eater,
   man-killer, manslayer, massacrer, matador, murderer, pesticide,
   poison, poisoner, punisher, slaughterer, slayer, thug, torpedo,
   trigger man