Phandelver and Below: The Shattered Obelisk, pg. 123
Sure-Footed. The skeleton has advantage on Strength and Dexterity saving throws made against effects that make it have the prone condition.
Battleaxe. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 1d8+3 slashing damage, or 8 1d10+3 slashing damage if used with two hands.