Pokémon Diamon and Pearl.
Well, most you can get after beating the game and getting national pokédex. With pokéradar, swarms, new places and such. Also more fossils underground.
Before that you have to know where they are, what time they appear and have the patience to wait. Go to an pokémon wiki site for help. You can also get either armor or skull fossil underground, revive those and have a rare pokémon. You also get Togepi from an egg and Happiny from an egg. :) And in platinum you'll get Eevee from Bebe and Porygon from a male in Veilstone City.
Torterra is a Grass and Ground type pokemon.
I don't know if you would call this rare, but if you want a ditto, you could find that with the poke radar. Just fly to canalave city, leave the exit (southeast). Walk a few steps east and you will see a patch of grass. step in it and use the poke radar. If one of the shaking pieces of grass are sparkling, go in it. It could be a ditto.
U have to chain. Spray yourself with a repel. Walk into a patch of grass. Use the Pokemon sensor.Kill or catch the Pokemon. Repeat. You must do it about 54 times more for rare Pokemon. Do not walk into different kinds of grass. Like one that is only shaking to one that shines. Do not save in the middle of a chain. The same Pokemon will never be in the grass closest to you don't EVER try it. I had a chain of 70 Makuhita and then I accidental walked into a patch next to me and broke my chain. And never go to a corner of the grass even edges are risky. That is a good way to break your chain. Doing these things will find a different Pokemon which is how you break the chain.
There is no TM you can get that makes Pokemon fall asleep, there is hypnosis, which u can not get as a TM, only certain Pokemon can learn it at a certain level, and there is dark void, and i believe only 1 Pokemon can learn that move and that's darkrai. theres also grasswhistle, obviously only grass Pokemon can learn it but that is also not a TM move. certain Pokemon randomly learn it.
Rare candies only raise a pokemon's level. There are no pokemon that need a rare candy to evolve. That being said, using a rare candy may elevate a pokemon to the level required for evolution.
Rare Pokemon come randomly when you're in the grass or cave.
look for grass that wiggles on any route. if you go into the grass a rare pokemon will appear. most of them are audinos though.
Look for them in the grass
It is rare on One Island
in the underwater grass but he is rare.
Running around in the grass randomly after the Pokemon league. You have to be very, very, lucky.
in rare places they are every where in the grass
click randomly that's how I got a celebi :D
You can find shiny Pokemon randomly through out the game.
No Pokemon can make rare candies, but some Pokemon have the Pickup ability which give them a chance of picking up items randomly including rare candies. Some of these Pokemon include Zigzagoon, Linoone, Meowth, and Sentret.
Go to any patch of grass and use the Poke Radar.
i don't know but for shiny Pokemon look for the shiny patch of grass with the pokeradar