Mental Burst. When the goblin dies, its pent-up mental energy explodes in a psychic blast. Each creature within 5 feet of it must succeed on a DC 13 Intelligence saving throw or take 5 (2d4) psychic damage.
Mental Fortitude. The goblin has advantage on saving throws against effects that would make it have the charmed or frightened condition.
Multiattack. The goblin makes two Unarmed Strike attacks.
Unarmed Strike. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit:5 (1d4 + 3) bludgeoning damage plus 3 (1d6) psychic damage.
Telekinetic Shove. The goblin targets one creature it can see within 30 feet of itself with a thrust of telekinetic force. The target must succeed on a DC 13 Strength saving throw or have the prone condition.
The specifics of how a psionic goblin comes to exist vary. Some are born, changed by energy leaking from the Far Realm. Others transform themselves with their psionic power or enter into agreements with other Aberrations, which help them transform in return for their service as shock troops. Regardless, the result is the same: a goblin with unnatural and barely contained psychic power.