Brain-Eating. The gu'en-deeko fighting ape has used its Brain-Eating power (see the base Gu'en-Deeko for details) and currently possesses the brain powers of a Gladiator, a Knight, a Drow, and a Bugbear (see pages 346, 347, 128 and 33 of the Monster Manual).

Brave. The gu'en-deeko fighting ape has advantage on saving throws against being frightened.

Brute. A melee weapon deals one extra die of its damage when the gu'en-deeko hits with it (included in the attack).

Fey Ancestry. The gu'en-deeko fighting ape has advantage on saving throws against being charmed, and magic can't put the gu'en-deeko to sleep.

Innate Spellcasting. The gu'en-deeko fighting ape's spellcasting ability is Charisma (spell save DC 13). It can innately cast the following spells, requiring no material components:

• At will: dancing lights
• 1/day each: darkness, faerie fire

Surprise Attack. If the gu'en-deeko fighting ape surprises a creature and hits it with an attack during the first round of combat, the target takes an extra 7 (2d6) damage from the attack.

Multiattack. The gu'en-deeko fighting ape makes three melee attacks or two ranged attacks.

Fist. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) bludgeoning damage.

Longsword. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) slashing damage,  or 16 (2d10 + 5) slashing damage if used with two hands. 

Spear. Melee or Ranged Weapon Attack: +8 to hit, reach 5 ft. and range 20/60 ft., one target. Hit: 12 (2d6 + 5) piercing damage in melee or 8 (1d6 + 5) piercing damage at range, or 14 (2d8 + 5) piercing damage if used with two hands to make a melee attack.

Shield Bash. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 10 (2d4 + 5) bludgeoning damage. If the target is a Medium or smaller creature, it must succeed on a DC 16 Strength saving throw or be knocked prone.

Heavy Crossbow. Ranged Weapon Attack: +5 to hit, range 100/400 ft., one target. Hit: 5 (1d10) piercing damage.

Leadership (Recharges after a Short or Long Rest). For 1 minute, the gu'en-deeko fighting ape can utter a special command or warning whenever a nonhostile creature that it can see within 30 feet of it makes an attack roll or a saving throw. The creature can add a d4 to its roll provided it can hear and understand the fighting ape. A creature can benefit from only one Leadership die at a time. This effect ends if the fighting ape is incapacitated.

Parry. The gu'en-deeko fighting ape adds 2 to its AC against one melee attack that would hit it. To do so, the fighting ape must see the attacker and be wielding a melee weapon.