It's possible by teamspeak 'bot', I don't know if it's legal but usually it shows all characters well.
Although it doesn't always work that way.
example: I enter my char Tynusiiaa, but he doesn't show me the character 8lvl. However, if I enter the nickname of this 8lvl, there is a chance that he will show 'Tynusiiaa' as the owner.
Same with TibiaRing, this costs 3euro for one time.
this is less realistic and shows only after logging in the possibilities that the owner can be.
this usually only shows characters that have been logged in for some period of hours. if you have 8lvl and you put them on offline training only probably they won't be shown.