The best replacement for crabs is scabies.

The best alternatives to crabs are rated as following:
★★★★★  scabies
★★★★★  lice
★★★  jock itch
★★  pubic lice
★★  body lice
★★  bed bugs
★★  lobsters
★★  dry skin
★  razor burn
★  king crabs
★  spiders
★  chlamydia
★  public lice
★  head lice
★  ticks
★  slobs
★  female crabs
  fish
  maryland crabs
  crabs
  experiments
  yaks
  stone crabs
  razor bumps
  snails
  male crabs
  steaming crabs
  crab
  craps
  red crabs
  fiddler crabs
  land crabs
  hard shell crabs
  dungeness

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

Other search terms related to crabs and their ratings are:
★★★★★ cichlids
★★★ pubic hair
★★ pubes
You have in mind a companion for crabs and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of crabs in all years. Click on graph for more.
crabs
scabies
lice