>>23130135Thousand Arrows is also neutral on all Flying types, but after they're knocked to the ground the damage is dependent on their other typing. Pelipper, Talonflame, Skarmory, and Dragonite were what I tested. All took neutral damage, despite Talonflame's and Skarmory's primary typings. When they were knocked to the ground the two were weak to subsequent uses though.
Levitating Pokemon don't neutralize it though. Gengar and Rotom-H took super effective damage from it when I tested it.