RTF is a global modification that replaces all towns in the game.

http://heroescommunity.com/viewthread.php3?TID=40354 You can find several creatures here.

Yes, I saw that mod. To be honest, nothing really appealed to me there.
But on the same forum, someone is adding objects from Heroes of Might and Magic VI into Heroes of Might and Magic V, so I think we can use that later :)

Added 1 minute ago
Although, I think I'll take the Lizardmen and add them... to the Fortress faction.