Bite

Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) piercing damage, and the target is grappled (escape DC 14). Until this grapple ends, the creature is restrained, and the hound can't Bite another target.

Slick Spittle

The eel hound covers the ground in a 5-foot square centered on a point it can see within 10 feet of it with its slippery spittle. Each creature standing in that area must succeed on a DC 13 Dexterity saving throw or fall prone. A creature that enters the area or ends its turn there must also succeed on a DC 13 Dexterity saving throw or fall prone. The spittle remains on the ground for 1 minute.