"Undesirable No.1": Harry Potter.
Undesirable No.1: Harry Potter.
An Undesirable is a criminally-wanted wizard by the Ministry of Magic, similar to a "Public Enemy" in the Muggle world.
From 1997-1998, Harry Potter was marked Undesirable #1, making him the most sought-after wizard by the government. The reward for the capture of him and his wand reached 200.000 Galleons in April of 1998.