If Monstro did not appear on your gummi ship map, there is a warp hole next to Wonderland. This should bring you to Monstro.
Generally Agrabah.
I'd suggest going by the Star Difficulty: Wonderland, Olympus Coliseum, Deep Jungle, Monstro, Atlantica, Agrabah, Halloween Town, Neverland, Hollow Bastion.
Kingdom hearts 2
Yes, monstro is in kingdom hearts, and he can be really confusing. just go in the door that riku went through (watch the cutscene) and everything else is pretty straight forward, just don't try and jump any gaps.
After you beat the Parasite cage once.
You can't.
roar
No, he does not
By defeating Jafar.
Generally Agrabah.
Probably Agrabah
They are in Agrabah and Neverland (Clocktower)
The original 3 and Aladin
I'd suggest going by the Star Difficulty: Wonderland, Olympus Coliseum, Deep Jungle, Monstro, Atlantica, Agrabah, Halloween Town, Neverland, Hollow Bastion.
Agrabah from fire type heartless
Agrabah
you go to the level that is monstro.