Trade with your friends as I am not to sure abt the code.. .
Use an action replay.(or at least thats my way of doing it...)
The action replay code for totodile in pokemon soul silver
Lboy201 is wrong, you can't put crystal in to a DS. You have to catch them in emerald then migrate them or use an action replay cheat
From Pal Park you can insert a gba game then mirgrate it from the old pokemon region games I think it's crystal but.
Use a code
2 get cyndaquil or the others, you have 2 trade it 2 emerald from the game that its on and then migrate from emerald! Now you have the correct answer!