Boomer Zombie

Undead Fortitude. If damage reduces the zombie to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.

Spit. Range Weapon Attack: +4 to hit, reach 15 ft., one target. Hit: 6 (1d6 + 3) Poison Damage. If the Blooter hits the target, it must make a DC 13 Con saving throw. On a failiur it is poisoned until the start of the Blooter's next turn. In addition the Spit contains pheromones that attract other Zombies. If a target is hit by the spit, every zombie in a 20 radius focuses for the next two round the target.

Explosion. If the Blooter is in melee range with an enemy it will explode as an action, killing itself in the process, and every creature in a 10 ft. radius must make a DC 13 Dex saving throw or take 15 (3d6 + 3) Poison Damage + 7 (1d8 + 2) Force Damage on a failed save and halfe as much on a succesful save. One a failed save each target must  make a DC 13 Con saving throw. On a failiur it is poisoned for the next 3 rounds. At the end of a creature's turn it can reroll the saving throw and the poison ends earlier on a success In addition the posion contains pheromones that attract other Zombies. If a target is hit by the poison, every zombie in a 80 radius focuses the targets for the next 5 round. The zombies automatically know the location of the targets. The Blooter also explodes if it dies. The poison has no effect on other undead creatures.