A disposable toilet seat cover apparatus is for use on the existing seat of a toilet. The apparatus is provided in a textured biodegradable water soluble material and resists slippage on the seat. A pull tab provides for the gas chamber within the valve assembly of the initially compactly folded apparatus to release a compressed gas to fill the seat cover/cushion. After use, the apparatus' biodegradable makeup provides for either discarding in a trash bin or for deposit into the bowl water, where the apparatus quickly deflates and dissolves. Any of the apparatus not immediately dissolved in the bowl water is easily flushed.