to find houndour you need to unlock mystery gift and you'll need another person to play mystery gift with you and then different types of Pokemon will appear in the altering cave.
Houndour can be caught in Altering Cave.The only place in-game for Houndour is in the Altering Cave, but you have to do something to make it appear. Other than that, you must trade or cheat.
At first only Zubat are found there, but using Mystery Gift with other players unlocks: Mareep Aipom Pineco Shuckle Teddiursa Houndour Stantler Smeargle
you'll never find any other Pokemon in the altering cave sadly
as i recall you can only find zubat in altering cave but after you do some certain event then you can find other Pokemon like teddiursa
Besides by trading or hacking... After obtaining the National Pokedex, you can find Houndour in Route 9. Catching a Houndour would be just like catching any other Pokemon. Bring its health down as low as possible without fainting it. Then, put it to sleep, paralyze it, or freeze it. Then use a ball that raises the catch rate of the Pokemon, such as an Ultra Ball.
Only on emerald after beating the elite4 can you get a houndour, However the only other possible way to get houndour is from Pokemon colosseum and trade it to firered then trade it to ruby or sapphire or emerald.
if you have houndour i dont know what to tell you but if you can't find houndour or houndoom it is because it is in the johto region , not hoenn region 8-(
You can catch Pokemon from other regions like stantler and other things but you need an event to catch them I know that's very lame but whatever
you have to use surf in it and you will find golbat
The only way to get Teddiursa is to trade from other games. In Firered Teddiursa is found in Altering Cave.
you could get the pokemon squirtle,bulbasuar,andcharizard but they are hard to find i found them you have to hack the game to get them easily and other rare pokemons easily
mystery gift is for the amaica rocks and i am still tryiny to figure out the other parts