No, Cradily can only learn Giga Drain through the Move Tutor in Humilau City from the Black 2 and White 2 games.
You can always transfer one to Pokémon X and Y by using the Poké Transporter and Pokémon Bank apps.
yes, becouse it is a grass tipe
giga drain
From my experience, you cannot find or buy the move Giga Drain In Pokemon Emerald. It is only a learned move. If you have a Shroomish, it will learn Giga Drain in one of its advanced stages.
Roselia learn giga drain at 25 before evolve to roserade.
No. It can't learn Mega Drain but it can learn Giga Drain.
Technically this is based completely on opinion however there are ways to tell by your style Cradily- Cradily learns more strategic moves like giga drain and ingrain stuff like that to make the battle last long but in your favor Armaldo-Armaldo is more of your powerhouse Pokemon this thing can be pretty vicious with the a solid power move. I prefer Armaldo myself
Giga Drain.
100
Level 25
Lombre cannot learn Giga Drain. It can be learned, if bred with a Pokemon who knows the move.
In Pokemon Beautifly learns the move silver wind at level 34. This Pokemon learns giga drain when it reaches level 38.
Garchomp cannot learn Giga Impact from leveling up in Pokemon Platinum. Garchomp can learn Giga Impact from the TM that teaches it which is TM68.