Nimble Escape. The goblin can take the Disengage or Hide action as a bonus action on each of its turns.

Magic Resistance. The goblin shaman has advantage on saving throws against spells and other magical effects.

Unstable Power. Every time the Yagooyagh uses a spell, cantrip or otherwise, they experience a wild magic surge and must roll on the wild magic table. 

Spellcasting. The Yagooyagh is a second level spellcaster. Its spellcasting ability is Charisma (spell save DC 13, +6 to hit with spell attacks). The Yagooyagh has the following wizard spells prepared:

Cantrips (at will): fire bolt, dancing lights, acid splash, message

1st level (4 slots): expeditious retreat, false life, thunderwave

2nd level (3 slots): web, levitate

Goat Staff. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d8 + 1) bludgeoning damage plus 10 (3d6) necrotic damage.

Redirect Attack. When a creature the goblin shaman can see targets it with an attack, the goblin shaman chooses another goblin within 5 feet of it. The two goblins swap places, and the chosen goblin becomes the target instead.