It has wings and feet, so how can it punch? (If it punches with its feet, wouldn't that be drain kick?)
The way it learns Drain Punch in black/white2 is by learning it by move tutor as a togetic, and then evolving into a togekiss. Now it knows the move, yet it has no fists. Since Pokemon games dont show direct contact between the Pokemon, the only way to see how it uses Drain Punch is the anime. Also, the move Drain Kick doesn't exist. I hope this helps! -Jellohamster
Togekiss lays an egg, when it hits the ground it cracks open, and there lies togepi. Then Togepi starts b**ch-slapping the opponent w/ Drain punch. Obviously.
Game Freak does what Game Freak wants.
It could be that it "punches" using its wing or its head. Or it could summon an otherworldly fist for all we know.