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@LadyskullfangVonWint
It is indeed a fungus. They thrive in hot wet weather. Put on a pair of gloves, and gently remove the fruiting body (mushroom). You can apply a fungicide to the soil, or just dust it well with cinnamon (yup..the stuff you make toast with) The actual fungus is in the soil, but the spores are airborne so the best way to handle them is with a fungicide if they become invasive.
Allow the soil to dry out some between waterings. (water when the top couple inches are becoming dry)