Leaper. The beast's long jump is up to 20 feet and its high jump is up to 10 feet, with or without a running start.
Spider Climb. The beast can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Relentless Rampager When the beast is reduced to 0 hit points but not killed outright, it can drop to 1 hit point instead. it can't use this feature again until you finish a long rest. Additionally when the beast reduces a creature to 0 hit points with a melee attack, the beast can use its reaction to move up to half its speed and make one attack. If it hits with that attack, it gains half of the damage dealt as temporary hit points.
Slam. Melee Weapon Attack: (your proficiency modifier + Its Strength modifier) to hit, reach 5ft., one target. Hit (2d6 + Its Strength Modifier) Bludgeoning Damage.
Bite. Melee Weapon Attack: +5 (your proficiency modifier + Its Dexterity modifier) to hit, reach 5ft., one target. Hit 6 (1d8 + Its Dexterity modifier).