Speed is doubled on held item loss; boost is lost if it switches, gets new item/Ability.
Pokémon with Unburden
Hawlucha
Hitmonlee
Treecko
Grovyle
Sceptile
Drifloon
Drifblim
Purrloin
Liepard
Accelgor
Swirlix
SlurpuffUnburden
Sun & Moon
Sun & MoonShowing Sun & Moon. Items may require trading, an event, or downloadable content.
HawluchaHitmonleeTreeckoGrovyleSceptileDrifloonDrifblimPurrloinLiepardAccelgorSwirlixSlurpuffSources: PokéAPI, PKHeX game records, Pokémon Showdown and Serebii.