Pokémon: Black & White 2

Wild Pokemon

Name	Type	Location	Encounter Rate
Rattata	Normal	Walking	45%
Zubat	Poison/Flying	Walking	45%
Grimer	Poison	Walking/Surf/Fishing	10% (Walking), 100% (Surf), 95% (Rippling), 100% (Fishing), 90% (Rippling)
Muk	Poison	Surf/Fishing	5% (Surf Rippling), 10% (Fishing Rippling)

Head down the stairs. When asked a question by Hugh reply with the top option ('Yes') and he'll tag along. His party is as follows:

If Snivy was your starter

Pokemon	Level	Type	Held Item
Pignite	20	Fire/Fighting	Charcoal
Pidove	18	Normal/Flying	-

If Tepig was your starter

Pokemon	Level	Type	Held Item
Dewott	20	Water	Mystic Water
Pidove	18	Normal/Flying

If Oshawott was your starter

Pokemon	Level	Type	Held Item
Servine	20	Grass	Miracle Seed
Pidove	18	Normal/Flying

You now need to explore the sewers. Walking around in this area triggers random battles as if you were walking through grass. What's more, all battles are double battles as if you were walking through dark grass. The double battles themselves work differently to normal double battles however.

Instead of you using two of your own Pokemon and controlling both, you control one of your own and Hugh controls one of his. Between every battle while Hugh is travelling with you, your Pokemon automatically heal ! Even if fainted, they're restored to full health. This also goes for Hugh's Pokemon.

Every time you begin another battle, it'll be at full health. This is an excellent opportunity to take advantage of, as you can train without the need to run back and forth healing you Pokemon whenever they become too weak. Once Hugh goes back off on his own, the healing between battles no longer occurs.

Note that all trainer battles here excluding the one involving the two Team Plasma Grunts, are single battles and Hugh will take no part in them.