From Bulbapedia, the community-driven Pokémon encyclopedia.
Grey (Japanese: グレイ Grey) is a Rocket Executive in the Golden Boys manga. Since Team Rocket no longer has a distinct Boss after Giovanni's departure, he seems to have taken the role of a highest member in the team.
He is first seen in Gold and Black VS Team Rocket at the Pokémon Summit in Ecruteak City, when Team Rocket tries to spoil the summit using radiomagnetic waves to confuse Trainers and their Pokémon in order to steal rare Pokémon gathered in that place. Gold and Black try to stop him using Espeon and Umbreon borrowed from Bill against his Houndour, but the Legendary beasts spoiled this fight and managed to ruin Team Rocket's deeds. Some grunts got arrested, but Grey seemingly managed to escape.
Later, he appears near the Whirl Islands, where Team Rocket does a money-making scheme by shipping people through the ocean for large sums of money (all other ships do not ship there anymore because of dangerous whirlpools), while Gold and Chris are sailing on the raft. Grey remembers Gold and orders to crush them by crashing the raft with his large ship. He succeeded in destroying it, but the heroes managed to escape by hiding in fog.