Infesting Growth. Any ally of the Devourer that starts it's turn in one of the Devourer's spell zone gains 6 (1D6 + 3) and has 3/4 cover.

Zerg Favoritism. Allies of the Devourer automatically make any saving throw the devourer forces them to make and they ignore difficult terrain created by Devourer spells. 

Zerg Spellcasting. The Zerg Devourer can cast any spell through one of it's Zerg allies if they are within 30ft of the Devourer.

Spellcasting. The Zerg Devourer is a 10th-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 14, +6 to hit with spell attacks). The Zerg Devourer has following Druid spells prepared:

Cantrips (at will): Infestation, Mold Earth, Primal Savagery, Thorn Whip  

1st level (4 slots): Entangle, Faerie Fire, Fog Cloud, Thunderwave

2nd level (3 slots): Dust Devil, Healing Spirit, Spike Growth

3rd level (3 slots): Erupting Earth, Sleet Storm, Wind Wall

4th level (3 slots): Blight, Giant Insect (Zerg), Grasping Vine

5th level (2 slots): Contagion, Insect Plague

Claw. Melee Weapon Attack: +2 to hit, reach 5 ft., one target. Hit: 2 (1d6 - 1) slashing damage. 

Stinger. Melee Weapon Attack: +2 to hit, reach 5 ft., one target. Hit: 6 (1d8 - 1) slashing damage and the target must succeed on a DC 14 Constitution saving throw or take 6 (2D6) Poison damage and be poisoned for 1 minute. 

Consume (Recharge 5-6). The Zerg Devourer can use a bonus action to deal 3D10 necrotic damage to any Zerg ally within 15ft, the Devourer gains health equal to half the damage dealt. If this damage kills the target ally this skill automatically recharges.