Sonans

Sonans is a tall, cyan Pokémon with a soft body. Its eyes usually appear scrunched, and it has a jagged upper lip. Female Sonans have a red marking on their mouth that resembles lipstick, while males do not. It has flat arms that are wider towards the tip and four stubby legs at the base of its body. There are two eyespots on its black tail. Sonans is very protective of its tail, to the point where it will suddenly turn uncharacteristically aggressive if the tail is attacked.

(Source: Bulbapedia)

Musashi's Sonans originally belonged to a different trainer until she accidentally traded her Beroringa for it. It has a tendency to break out of its Pokéball whenever it feels like it, usually to the dismay of the rest of Rocket-dan, and often joins in when they are blasting off. Sonans is the only Pokémon Rocket-dan obtained in the Original Series that is still part of their team today.