Red Mushrooms are already part of every new Creativerse gameworld at the start and can mainly be found on green Grass-blocks on the surface 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 away.
To pluck Red Mushrooms no Power Cells are required.
These mushrooms can also be found in Wood Treasure Chests occasionally, and as random drops or pet-harvest from Pigsies, Night Pigsies, Night Hoglets or especially often from BossHogs (in Savannah biomes) as well.
One small patch of 5 little Red Mushrooms that fit in one block will turn into only one (unit of) Red Mushroom(s) in your inventory.
You can either pick Red Mushrooms up directly (with your right mouse-button as the default setting) or you can take the block of Grass they're growing on to receive both the block and the Mushroosm together.
Red mushrooms cannot be placed, instead they will be eaten by the player-character if used.
Red mushrooms can be consumed either from a quickbar (drag it there with the mouse-cursor by holding left-click from your inventory if needed) with right-click; or by dragging them with the mouse-cursor by holding the left mouse button from the inventory over your player character's portrait in the equipment-window on the right side of the inventory.
Red mushrooms will heal 280 of maximal 1000 health points (shown on the red bar) within ca. 15 seconds (indicated by a heart-symbol on the left side of the screen).
Cooldown: once a Red Mushroom was consumed and the healing-effect starts, you cannot immediately consume another red mushroom, but will have to wait until the first one has finished its healing effect - said 15 seconds.
However you can consume other Mushrooms (Brown Mushrooms, Glowing Mushrooms), Potions and/or Food while the healing-effect of the Red Mushroom is still ongoing. You can also use the healing effects of Mineral Water and/or Healing Beacons while being healed by a Red Mushroom at the same time.
A number of crafting-recipes are currently (R41 in April 2017) demanding Mushrooms of any kind, which is indicated by blue arrows on the Mushroom icon in the crafting recipe. You can click on this icon to choose other Mushroom types to craft this recipe. Examples would be Basic Health Potions, Advanced Health Potion2, Stone Mining Cells, Obsidian Mining Cells and Taming Collars.