Mewtwo (average/only level 70)
Primape (average level 55)
Ditto (average level 55)
Kadabra (average level 58)
Parasect (average level 56)
Machoke (average level 46)
Slobro (average level 50)
Slopoke (average level 36)
Golbat (average level 48)
Magneton (average level 50)
Wobbafet (average level 58)
Note:Don't use a master ball to catch Mewtwo use a ton of ultra balls because you will want to save the master ball to catch another legendary pokemon. You will find it randomly in a pacth of grass. As soon as you attack, it will try to flee so either have a Wobbafet (I don't know how to reall spell the name) or just use a master ball right of the bat.Make sure you take a Pokemon that knows flash, rock smash, strength and rock climb to get the items of this cave as well as, you guessed Mewtwo. Take a dark type when you face it because the only damage inflicting move Mewtwo knows is psycho cut which is a psychic type move so it won't do any damage.
Many pokemon are found in the Cerulean Cave, but the one I believe you are refering to- "I heard of a cave here that had a horribly powerful pokemon in it..." is Mewtwo
(that quote is from a child outside the cave, I think it is where the question stems from)
In the cerulean cave, there is the historical place where you can find mewto at the deep sides. posted by: joseph_ck16
You cannot visit Cerulean Cave in Gold version, it has been closed off. It's still in the same place as Red/Blue/Yellow though, across the water in Cerulean City.
Just norh of cerulean city in the Kanto region.
It's a mewtwo. Just like in the classic red, yellow, and blue versions
MewTwo but you have to search hard
Mewtwo
Well, you have to get a electricity Pokemon and level it up until it learns thunderbolt simple!
You can't get Regigigas in Pokemon Soulsilver or Heartgold. However, Regigigas is available in Pokemon Diamond, Pearl, and Platinum by obtaining Regice, Regirock, and Registeel. Once you have done that, you can take all three of them to the Snowpoint Temple in Snowpoint City to battle a lv.1 Regigigas.
By the diglet's cave. You need to wake up the Snorlax
Mewtwo is in cerulean cave, and you can only get Mew through an event.
On Heartgold and Soulsilver versions, the ice path is located right outside of route 44. After you defeat the trainer next to the cave entrance,you can go inside.
The Odd Incense can be found in the Cerulean Cave along with Mewtwo himself.
Cerulean Cave
In cerulean cave
Cerulean Cave.
You can get all the Pokemon in the cerulean cave where you find celebi below the cerulean cave.
cerulean cave
Yes in Firered/Leafgreen and Heartgold/Soulsilver
Southeast from the middle of the cave
Yes in the Cerulean Cave.
Cerulean cave
There is one in Cerulean Cave.
In HeartGold and SoulSilver go to Cerulean Cave it is at Level 70.