How do you get the horned reaper on dungeon keeper?

Here : http://digiex.net/games-downloads/159-dungeon-keeper-2-full-version-1-7-a.html

No.

For any sacrificing you'll need a Temple, at least 3*3 square big. Pick up the creature you want to sacrifice, and drop it into the central pool of your Temple.

Sadly, Dungeon Keeper 2 is not legally abandonware as the assest was transferred in the purchase of Bullfrog by EA.

Off of iTunes dipwad