The best replacement for amumu is rammus.

The best alternatives to amumu are rated as following:
★★★★★  rammus
★★★★★  udyr
★★★★  malphite
★★★  nasus
★★★  vi
★★★  evelynn
★★★  fiddlesticks
★★  zac
★★  mundo
★★  singed
★  hecarim
★  shen
★  shaco
★  sejuani
★  dr mundo
★  alistar
★  vi jungle
★  nocturne
★  warwick
  teemo
  cho'gath
  leona
  skarner
  blitzcrank
  nautilus

Your alternative for amumu is not listed? Suggest!
Speaking about amumu, one probably shouldn't forget about spell vamp.

Other search terms related to amumu and their ratings are:
★★★★★ spell vamp
You have in mind a companion for amumu and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of amumu in all years. Click on graph for more.
amumu
rammus
udyr