on 1:TEXT:*:#: {
  if ($nick == %nick) .msg # $1-
}
on 1:ACTION:*:#: {
  if ($nick == %nick) .describe # $1-
}

Menu nicklist {
  [Mimic]:/set %nick $1 | echo Mimicing $1
  [SMimic]:/echo You Have Stopped Mimicing %nick | /unset %nick
}