Chestnaught gets Spiky Shield @ lv 36 and I wanna know whether it deals neutral (spikes style) damage or if it deals Grass type damage to attackers making physical contact.
If the opponent uses a contact move on Chesnaught while it uses the move, they'll take a set amount of damage; just like Spikes.
Additionally, if Spiky Shield blocks an attack that would make contact with the user, the attacker suffers damage equal to 1/8 of its maximum HP.
http://bulbapedia.bulbagarden.net/wiki/Spiky_Shield_(move)