Nothing exept there is a room in solaceon ruins connected to it which has hippopotas , unown! and unown? (p.s this only works if you have all 26 althabitcal unown)
Hippopotas is in Ruin Maniac's Cave.
you will find hipopotas right below vailstone city in a cave called Ruin Maniac Cave. Beat a Pokemon than use a max repel. After, use sweat sent and a hipopotas will appear.
ruin maniac's cave route 214 near veilstone city
On Route 212 past the Ruin Maniac's Cave, the Magmarizer is an item on the ground near a trainer with a Sheildon.
first catch all the unknown. then go to the ruin maniac guy . he will be done the tunnel go in it and at the end of it you should find them.
The ruin maniac is under veilstone city in the cave on the left.
It can be found in Ruin Maniac's Cave or Ruin Maniac's Tunnel by walking.
Ruin Maniac Cave
You can get the TM28 (Dig) on Route 214 in the Ruin Maniac Cave in Pokemon Diamond.
It leads to a room with unknown shaped like this ? and !.
You can find TM Dig at the Ruin Maniac Cave.
well, dig isn't a HM in Pokemon diamond, but it is an TM. anyway, you can find it on route 214, inside a cave where you'll find the ruin maniac- the same place where you find hippopotas.
The Pokemon Unkown.
if you mean the ! and ? unown you can, that's how you get them anyway!
http://www.youtube.com/watch?v=FZ-25C0JskM Watch this it shows you K
get an known for him
Hippopotas has an chance of spawning in the Ruin Maniac cave. The chance of encounter is about 1/20 so it may take awhile.