Just a guess, but do you have the begin and end?

From the help file...
Code:
alias animal {
  if ($1 == begin) return -
  if ($1 == 1) return Cow:echo Cow
  if ($1 == 2) return Llama:echo Llama
  if ($1 == 3) return Emu:echo Emu
  if ($1 == end) return -
}