The best replacement for tails is luigi.

The best alternatives to tails are rated as following:
★★★★★  luigi
★★★★★  sonic
★★★  knuckles
★★★  tails doll
★★  amy
★★  rouge
★★  shadow
★★  liberte
★★  eggman
★★  tails
★★  heads
★★  whonix
★  tor
★  twilight
★  dr eggman
★  yoshi
★  dark tails
  head
  no tails
  kali
  pony tails
  fins
  twilight sparkle
  tales
  heads nor tails
  tuskegee airmen
  sonic exe
  2 heads

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

Other search terms related to tails and their ratings are:
★★★★★ tor
★★★★ amy
★★★★ sonic
★★ waistcoat
★ cosmo
★ black tie
You have in mind a companion for tails and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of tails in all years. Click on graph for more.
tails
luigi
sonic