Is it possible to transfer toons between accounts for WotLK Classic?
It looks like you can’t… but I’m not an expert; I’m merely reading the Support Article here:
(ensure you select Wrath of the Lich King Classic tab)
Specifically, it says:
It is not possible to transfer a Wrath of the Lich King Classic character to another WoW account or Battle.net account.
Finally… you should note that this is not the correct forum for WoW Classic.
This forum here is for technical support on Blizzard Classic Games… Diablo II (2000) and its extension, mostly. WoW (both Retail and Classic) have their own forums here:
Best of luck with this.