Walker

Long arms - the walkers long arms give it extra reach when attacking and can be used for it to block.

Swing - Melee weapon attack: +4 to hit, reach 15 ft, one target. Hit: 3d10 + 4 B

grab - +4 to hit, reach 15 ft, one target. once grabbed, a creature is restrained and stunned. once per the Walker's turn, the Walker can choose to squeeze the creature. the creature takes 1d6 for each turn it has been squeezed. a creature that is not grabbed can free a grabbed creature by making a strength check against a DC of 12.

Throw - a creature grabbed by the Walker is thrown up to 60 feet in a random direction and knocked prone. If a thrown target strikes a solid surface, the target takes 1d6 B for every 10 feet it was thrown. If the target is thrown at another creature, that creature must succeed on a DC 16 Dexterity saving throw or take the same damage and be knocked prone.

screech - the Walker can produce a high frequency sound, similar to the spell shatter. all creatures within a 60 ft circle must make a charisma or constitution saving throw. if they fail a charisma saving throw, they are frightened until they are 80 ft of the walker. if they fail a constitution saving throw, they take 5d10 psychic damage. after using the screech, the Walker can't use it again until after 3 of its rounds.

Block - if the walker were to be attacked head on, it can choose to block with its arms, the attacking creature must make an attack roll on the arms. the arms have a AC of 10 and an HP of 10. once the arm has been destroyed, the Walker can't block with that arm.