If you mean follow you around in the adventure mode (walking around and stuff) then no, not in Pokemon Emerald.
you can't get the black flute in leaf green but you can in Pokemon ruby, sapphire and emerald then trade it to leaf green.
go to mossdeep city then head left and go past the white rock at the end their should be a house with a fisherman in it and he will give it to you
latios and latias appear in random patches of grass and areas of water after you catch Rayquaza or make him faint.(after saving the world in Sootopolis.)
ABXY
Sadly, no. The creators of the game forgot to add in the Pokedex, so trading is impossible without GameShark. :(
use action replay
Go to the weather institute where you got the Pokemon "castform." The guy that gave you it will tell you to go to a route. Go there and look for a cave, dark water or things like that. It is usually raining. Warning: Make sure to bring Pokemon that know the moves dive and flash. Note: You will need to beat the elite four before you can capture kyogre.
dfg tyhgtg
You can download it at 4 SHARED.
at mt. pyre
yes there is. just fly there if you can
well you have to have mewtow and change one to zacrom and then get a pekachu and get 6 enrgy cards and then get one more mew tow and leave it how it is and get i traner and that would be how to do it