I goggled it - In a old Superman comic it explained that to cut his fingernails, hair and beard Superman would enlist the powers of Super girl and Krypto the Superdog, and with their combined power of heat-vision focused on each respective of nail or hair they could keep Superman meticulously well-groomed. Cheers and happy weekend!
This post was edited by Nanoose at February 29, 2020 6:55 PM MST