The Sinnoh Collection Challenge is a limited-time event in Pokémon Go. You’ll be tasked with capturing nine different Pokémon for the event, and by collecting them all, you receive a badge showing you’ve done it. It costs towards your Elite Collector Medal, and the badge you receive has a number on it showing what place you received before other trainers. One Pokémon you need to capture for this collection is a Shadow Stunky.

The only way to capture a shadow Pokémon is to battle against a Team Rocket member. Thankfully, to capture a shadow, Stunky, you do not need to battle the Team Rocket leaders. All you have to do is fight against one of the grunts. You can find them hanging out by a PokéStop that they’ve taken over, or they will fly near your trainer position in a hot air balloon. Unfortunately, not every Team Rocket Grunt has the same Pokémon reward after you beat them. You need to defeat a specific one.

The Team Rocket Grunt you’re looking to battle against is the Dark-type one. They have a specific dialogue you want to look for when fighting them. They will be a female, and they will say, “Wherever there is light, there is also a shadow.” If they say something other than this line, you can expect not to capture a Stunky at the end of the fight. Because you’re on the clock for this challenge, run through as many Team Rocket members as you can to have them say this specific line. If you cannot leave your home, it might be a bit difficult to complete this challenge.

Once you capture this Pokémon, it will count towards your collection. Plus, you receive a new Pokémon to your roster, and Stunky is pretty decent.