Any Pokemon which is Flying type or has Levitate
All flying types are immune, yay!
That means Pokemon like Landorus, Togekiss etc. etc. all get to bypass that hazard
Also any Pokemon with White Smoke or Clear Body is immune as well. That means Torkoal, Metagross etc.
Pokémon with the ability Contrary get the Speed Boost instead of a speed drop - eg. Seperior and Malamar
Levitate as you know, also avoid Sticky Web
Any Pokemon holding the item Air Balloon also dodges it.
>Sticky Web sets an entry hazard around the opposing Pokémon, which lowers their Speed stat by one stage upon switching in. It doesn't affect Flying-type Pokémon, those with the Levitate ability, or Pokémon holding an Air Balloon. Pokémon with the Ability Clear Body and White Smoke will not have their Speed lowered, and Pokémon with the Ability Contrary will instead have their Speed raised by one stage. Sticky Web triggers the effects of the Abilities Defiant and Competitive.