Monster Manual, page 163
Rampage. When the gnoll reduces a creature to 0 hit points with a melee attack on its turn, the gnoll can take a bonus action to move up to half its speed and make a bite attack.
Multiattack. The gnoll makes three attacks: one with its bite and two with its claws. Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 6 (1d6 + 3) piercing damage, and the target must succeed on a DC 12 Constitution saving throw or take 7 (2d6) poison damage. Claw. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) slashing damage.
Desert, Forest, Grassland Hill