Check out this screenshot (Heroes 3 + Photoshop).

the second two images are from earlier versions of Heroes 3 (before the release of The Restoration of Erathia).
all the images, including the first one, have been on the DF2 forum in the "screenshots from Heroes" thread for months/years. by the way, there's a lot of other interesting stuff there too..

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for example, here. an earlier version of Heroes, where a monster was planned - something like a green skull.