Want this question answered?
Move the puzzle pieces to look like Kabuto.
After solving the puzzle in tanoby key you can go inside the tanoby chambers and capture the Pokemon Unown.
i don't know about a mystical pokemon, but if you solve the puzzle in Tanoby Key (which is the cave in seavault canyon) Unown appear in the Monean ruin. Solve the puzzle in Tanoby Key by putting all the boulders in the holes.
If you use gameshark maybe.. but why would you want to get a missingno? It might ruin your data.
go to the ruin of alpha and go to the temple near the top solve th puzzle then you fall in and all the unknow start appering
The Pokemon Unkown.
to get to ruin valley on Pokemon leafgreen you have to get the ruby in mt. Ember and bring it back to celio then go to six island
On six island a ruin maniac in ruin valley has a golem.
The ruin maniac is under veilstone city in the cave on the left.
Hippopotas is located in the Ruin Maniac cave in Pokemon Platinum.
Move the puzzle pieces to look like Kabuto.
It can be found in Ruin Maniac's Cave or Ruin Maniac's Tunnel by walking.