The Creature Portal is a unique building in Heroes of Might and Magic IV which allows Preserve towns to recruit a number of different creatures. Once the portal is built, the player can train any of the four elementals: fire, a ranged attacker; water, an illustrious spellcaster; earth, a powerful tank; and air elemental, a speedy flyer. The leprechaun and satyr are great team players, each can cast a beneficial spell. The mantis is one very skillful creature. Then there is the waspwort, a plant creature with a weakening ranged attack.
The creature portal works like this: The town gets a certain amount of "points" each day that can be put towards portal monsters. The amount that can be recruited is equal to the number of points accumulated so far. Stronger creatures cost more points.