This is a very small known character, so here is a very brief description from HP Wiki. ;)
Bertram Aubrey – Hogwarts student bullied by James Potter and Sirius Black
Bertram Aubrey's Sorting
"Aubrey, Bertram." Called McGonagall. The first boy strode up, brown hair falling into his eyes. He sat down huffily, as a boy had just made fun of him, and he had gotten yelled at for attempting to curse him.
Ugh, my boy this is too easy-SLYTHERIN!
Bertram rolled his eyes, and walked over to the snake table. It was obvious that he would be placed there, much like the long line of wizards in his family. He glared at the boy who had taunted him. Sirius Black.