Wally, after losing 2/3 of his hp will lose his fire resistance and gain the abilities Blood Cough and Neck Snap. Wally will make an attack for ever member of the party.
Scratch | 1 | 1d8
Grasp | 2 or 5 | 1d4 Enemy is grappled and must make either a str or dex save to escape.
Laugh | 3 | All enemies must make a cool saving throw or have disadvantage on all action their next turn.
Grope | 4 or 6 | Enemy must make a composure saving throw or have disadvantage on their next attack roll.
Blood Cough | 5 | 1d6 Wally takes 1d4 damage.
1d4 Neck Break | 6 | Enemy is incapacitated.