To trigger the Free Spins Feature in Zombie Carnival, you will need to land two Scatter Symbols on the reels at the same time during the base game play. Once this has occurred and the free spins round begins, the Scatter Symbols that brought the feature into existence will then morph into Wild Symbols and stick on the screen for every free spin until the feature draws to a close.
As you start, you will be given six free spins. From here, each Wild Symbol on the screen will take over any Scatter Symbols it finds on the reels and take up their position. Plus, as it goes about this action, the multiplier will be increased by 1X. This multiplier will then affect each winning combination that features that Wild Symbol.
Keep in mind that if you manage to land more Scatter Symbols than Wild Symbols on the reels simultaneously, any Scatter Symbols that are not consumed by the Wild Symbols will also morph into Wild Symbols and act in the same way as any other Wild Symbols that trigger the feature. Plus, each time a Scatter Symbol lands during the Free Spins Feature, an extra free spin will be added onto your total tally.