When the smell of passing thoughts piques its hunger, its maw becomes primed with acid and a taste for brains.

Kederekt Parasite

Whenever an opponent draws a card, if you control a red permanent, you may have this creature deal 1 damage to that player.

Duskmourn: House of Horror Commander

Whenever an opponent draws a card, if you control a red permanent, you may have Kederekt Parasite deal 1 damage to that player.

The List

Conflux

The "intervening 'if' clause" means that (1) the ability won't trigger at all unless you control a permanent of the specified color, and (2) the ability will do nothing unless you control a permanent of the specified color at the time it resolves.