Swampert (5e Creature)
From D&D Wiki
Medium elemental, any alignment
Torrent. While it has 40 hit points or fewer, the swampert has advantage on attack rolls. In addition, it deals an extra 7 (2d6) damage to any target it hits with an attack.
Damp. Fire and electric damage are halved if the effect passes within 5 feet of the swampert to reach its target.
Multiattack. Swampert makes one slam attack and uses Mud Sport if it can.
Slam. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) bludgeoning damage.
Muddy Water. The swampert spews forth a wave of liquid mud. All creatures within a 20 foot cube in front of it must make a DC 15 Strength saving throw. On a failed save, a creature takes 7 (2d6) bludgeoning damage, falls prone, and is blinded until the end of its next turn. On a successful save, a creature takes half as much damage and isn't knocked prone or blinded.
Mud Sport (Recharge 5-6). All creatures within 10 feet of the swampert must succeed on a DC 15 Constitution saving throw or be blinded for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on a success.