The best replacement for snails is slugs.

The best alternatives to snails are rated as following:
★★★★★  slugs
★★★  oysters
★★  shrimp
★★  pleco
★  crabs
★  hermit crabs
★  mystery snails
★  escargot
★  turtles
★  worms
  slugs faster
  land snails
  snakes and snails
  water snails

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

Other search terms related to snails and their ratings are:
★★★★★ goldfish
★★★★ cichlids
★★★ bettas
★★ betta
★ betta fish
★ african dwarf frogs
You have in mind a companion for snails and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of snails in all years. Click on graph for more.
snails
slugs
oysters