This time drew something ("M") on it. It lives up to its name.

On stumps and trunks of deciduous trees, especially beech; rarely conifers

Inedible — woody and tough

• ▸ Large, flat grey-brown bracket with a dull, crusty top surface
• ▸ White pore surface that turns brown permanently when scratched
• ▸ Concentric growth zones on the upper surface
• ▸ Woody, hard, perennial fruit body

Being totally woody, it can last for years. Draw on the fresh white underside with a stick and the picture remains permanently — origin of the name Artist's Bracket.