Currently (as of R41 in April 2017) there are 3 kinds of Mushrooms in Creativerse:
Many crafting-recipes will accept either of these mushrooms as ingredients. In that case the recipe has to be selected first, then the mushroom-icon can be clicked on to browse through the alternative options and choose one.
Mushrooms can be consumed either from the quickbar with right-click, or by dragging them with the mouse-cursor by holding left-click from the inventory over the character's portrait in the equipment-window on the right side. Mushrooms currently cannot be placed, instead they will be eaten by the player-character if used from a quickslot.
All Mushrooms will heal 280 health points (as shown on the red bar of maximum 1000 health for player characters) over time for ca. 15 seconds (indicated with a heart-symbol on the left side of the screen).
Once a Mushroom is consumed and the healing-effect starts, no other Mushroom from the same type can be consumed until the healing-effect (15 seconds) has finished.
However you can consume other types of Mushrooms, Potions and/or Food while the healing-effect of one type of Mushroom is still ongoing. You can also use the healing effects of Mineral Water and/or Healing Beacons while being healed by one to three Mushrooms at the same time.
Red Mushrooms can be found on the surface of any Creativerse-gameworld on green Grass in Forest-biomes, Woodlands, Grassland and in valleys between Mountains - growing there in patches of 5 Mushrooms each.
Red Mushrooms will also slowly regrow (meaning that more mushrooms will grow in time, however only 1 unit at a time) in time during the day on unlit spots, sometimes even on Dead Grass, especially in areas where all Red Mushrooms had been plucked.
Red Mushrooms can also be discovered in Wood Treasure Chests occasionally, and can be obtained as loot or Pet-harvest (very often) from BossHogs, or sometimes from Pigsies, Night Pigsies, Night Hoglets and other creatures.
To pluck Red Mushrooms no Power Cells are required.
Brown Mushrooms can be found directly under most surface layers of the world and embedded in Dirt in the Fossil layer nearly all throughout any Creativerse gameworld, except for under Mountains, Canyons and Oceans.
To harvest Brown Mushrooms no Power Cells are required.
They have the shape of Siltstone blocks with blueish Mushrooms inside that protrude from the block and give off a faint blue glow. However when harvesting them only 1 Glowing Mushroom each will be obtained, with no additional rocks.
Currently (R41 in April 2017) Glowing Mushrooms are necessary ingredients for crafting Iron Mining Cells with no alternatives.