I heard a rumor that the TM for Shadow Ball was in Reversal Mountain while EV training my Shiny Gengar. Heading over to the location I was given I was attacked by 2 Grumpigs at the same time! However one of this Grumpigs was different it was yellow bodied whereas its friend was pink as normal. It was a shiny Grumpig my second that day dont even possess the shiny charm on Black 2. I send out my Shiny Gengar and my ingame teams Excadrill. I switch to Golduck with Cloud Nine to remove sandstorm damage dont want my shiny Grumpig dying and finsih the standard Grumpig with Strength. 2 Repeat balls and a Nest Ball later Shiny Grumpig was mine .