If the ogrepede moves at least 10 feet straight toward a creature and then hits it with a slam attack on the same turn, the attack is treated as though the ogrepede scored a critical hit, but attack rolls against the ogrepede have advantage until the start of its next turn.

When the ogrepede scores a critical hit, each creature within 5 feet of the target must succeed on a DC 16 Wisdom saving throw or be frightened of the ogrepede for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to the ogrepede’s Overwhelming Assault for the next 24 hours.