Other known variants
x2Intimidating Fang
As long as Arbok is your Active Pokémon, any damage done to your Pokémon by an opponent's attack is reduced by 10 (before applying Weakness and Resistance).
ToxicThe Defending Pokémon is now Poisoned. Put 2 damage counters instead of 1 on the Defending Pokémon between turns.
Does Pyroar's "Intimidating Fang" Ability reduce damage from "Shred" attacks?
Yes, it does. The effect of Intimidating Fang is on the Attacking Pokemon (not on Pyroar), so Shred's condition of "any effects on your opponent's Active Pokemon" does not apply.
Does Pyroar's "Intimidating Fang" Ability reduce my opponent's Attack's damage, even when done to a Benched Pokemon?
Intimidating Fang says, "attacks used by your opponent's Active Pokemon do 30 less damage." Since it does not specifically designate Active or Benched Pokemon it reduces damage by -30 to each Pokemon that would be damaged by the opponent's attack.
Does Sandile's "Intimidating Fang" Ability also reduce damage done to Benched Pokemon?
Yes, it reduces all damage done by the opponent's Active Pokemon. Damage to your Defending Pokemon, your Benched Pokemon, and even damage done to your opponent's own Pokemon!