The best replacement for worms is viruses.

The best alternatives to worms are rated as following:
★★★★★  viruses
★★★★  birds
★★★★  birds lyrics
★★★  mucus in stool
★★★  caterpillars
★★  parvo
★★  virus
★★  mucus
★★  pregnant cat
★★  candida
★★  hemorrhoids
★  maggots
★  grubs
★  snakes
★  trojans
★  parasites
★  gunbound
★  eggs in stool
★  maggots in dog poop
★  angry birds
★  nightcrawlers
★  worms
★  earthworms
★  piles
  tape worms
  undigested food
  flat worms
  powerbait
  chicken liver
  lemmings
  minnows
  meal worms
  superworms
  helminths
  round worms
  gummy bears
  snails
  larvae
  hook worms
  hemmroids
  night crawlers

Your alternative for worms is not listed? Suggest!
Speaking about worms, one probably shouldn't forget about teeth.

Other search terms related to worms and their ratings are:
★★★★★ teeth
★ cats
kittens
rabbits
dogs
dirt
You have in mind a companion for worms and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of worms in all years. Click on graph for more.
worms
viruses
birds