Josh M. was a child that lived on the Federation colony of Omicron Theta during the early-to-mid 24th century. He was among those killed when the planet was ravaged by the Crystalline Entity in 2338.
He drew a picture of the colony being attacked by the Entity, which was later discovered by the crew of the USS Enterprise-D.
This drawing was brought aboard the Enterprise. With the report of Lore, this artwork aided the starship's computer in its reconstruction of the entity. (TNG: "Datalore")