The complete Pokemon Diamond and Pearl pokedex, part 6

Pokémon Name: Hippopotas
Type: Ground
Classification: Hippopotamus
Pokédex Number: 122 Sinnoh / 449 National
Abilities: Sand Storm – Creates a sand storm when entering battle
Dream World ability: Sand Force – Rock, Ground and Steel-type attacks get 30% power boost during sandstorms and gives user immunity to sandstorm damage
Useful Attacks: Sand Tomb
Location Found:
D/P/P: Maniac Tunnel (off Route 214)
HG/SS: Safari Zone (Desert area, post-National 'dex)
B/W: Route 4 (swarm)

Everyone loves hippos, and Game Freak is no exception. Normally hippopotamuses bathe in the mud, but this Ground-type Pokémon uses it as a weapon, summoning a sandstorm as soon as its released from its Pokeball. As one would expect from a hippo Pokémon, Hippopotas has a lot of HP and moves slowly, but its attacks pack a lot of punch.

Evolves into Hippowdon at Level 34.