Related to this question http://pokemondb.net/pokebase/7654/shadow-moves
almost all of the Pokemons learn shadow moves by snagged? what is snagged?
dont vote down please!!
You "snag" a pokemon, because in colosseum and XD, the main way of catching pokemon is by stealing them from other trainers. You character has a snag machine worn on their arm which lets them steal shadow pokemon.
http://www.youtube.com/watch?v=MLoSBPajcFE
Snagged means that you stole the Pokemon from the trainer via the means of the snag machine strapped to your arm in Pokemon coliseum / XD
