Keen Sight: Advantage on sight-based Perception checks.
Multiattack: The roc makes two attacks: one with its beak and one with its talons.
Beak: +13 hit, reach 10 ft., 4d8+9 piercing damage.
Talons: +13 hit, 4d6+9 slashing damage, and the target is grappled (escape DC 19). Until this grapple ends, the target is Restrained, and the roc can't use its talons on another target. If the target was standing on sandy ground, the roc can make a Sand Attack as a bonus action.
Sand Attack: The roc beats its wings and kicks up dust and debris at its feet. Each creature within 15 feet of the roc must make a DC 19 Con save or be Blinded until the start of the roc's next turn. The roc can only use this attack if it is within 5 feet of sandy ground.