Actually, I'm not sure if this is Onfim or not, since I don't read Old Novogrodian. But there was a kid named Onfim. And he did do a lot of drawings of himself with his dad and with his mom. And riding a horse, stabbing someone with a spear. All the usual stuff that medieval kids drew onto birchbark in 13th century Russia.
The Art of Onfim, excerpts and reproductions from 1957 archeological reports [slavic.freeservers.com, all via metafilter, thanks dt reader Eric
