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

If you delve into Disciples 3, you can find a lot of material for the mod: there's a Reaper there, with 8 arms, each holding a scythe. You can use him as a hero (attach him to a Dryad model, and when he casts spells, he simply floats slightly upwards, surrounded by a lot of green light). Nosferatu (he has a rather complex system due to artifacts – in Disciples, they introduced a feature where equipping artifacts of level 2 and 3 changes the texture of the hero itself) – you can take his hands, feet, etc., separately, and use them like Death Knights. There are vampires, one standing with a sword (on a standard model) and one with large claws (on a Bone Thrower model), and you can recolor another one and use it as well. They have ghosts, three flying women, which can be placed on a Dryad model. There's a Wyvern, a Dracolich, and others, which can be placed on a Hydra model. When Hydras attack, their heads tilt; you can leave this as is and add an acid breath attack (if you introduce them as neutral units).

Added 2 minutes ago
You can also take and introduce werewolves as neutral units, placing them on the model of Goblins, as some kind of ancient allies of the Undead.

Added 2 minutes ago
You can also take Goblins; there are three of them (warrior, archer, and mage).

Added 6 minutes ago
The problem is that I don't know how to extract the textures, because they are in .orc archives (if I'm not mistaken), and they can't be opened with a simple WinRAR.

Added 2 minutes ago
There are also many textures for Demons, and for Elves (but we don't have many of them), and for Humans (tons of knights fighting for the light, electric mages, and female healers).

Added 1 minute ago
You can also take some textures from Eador; there are many undead there, but they don't have an upgrade (you'll have to recolor the textures)