IADnDMN Stream Monsters! (2018/12/12)
As always, tune into ItsADnDMonsterNow's weekly monster-making stream on Twitch every Wednesday at 11am Pacific! We hang out, talk DnD, and make monsters together as I explain my process and share my tips for making fun and effective monsters that you can use in your own games!
Kukulkan, the Plumed Serpent
Suggested by Patron and Twitch viewer @whistlehunter, based on the mesoamerican legend, and specifically this artistic rendition from ArtStation artist (and concept artist at Riot Games) Simon Duboc.
Kukulkan
Gargantuan fiend (demon, shapechanger), chaotic evil
Armor Class 18 (natural armor)
Hit Points 350 (20d20 + 140)
Speed 50 ft., fly 80 ft.
STR DEX CON INT WIS CHA 27 (+8) 16 (+3) 24 (+7) 10 (+0) 15 (+2) 23 (+6)
Saving Throws Dex +11, Con +15, Wis +10, Cha +14
Skills Acrobatics +11, Athletics +16, Perception +10
Damage Resistances cold, fire, lightning, radiant
Damage Immunities poison; bludgeoning, piercing, and slashing from monmagical attacks
Condition Immunities charmed, exhaustion, frightened, poisoned
Senses truesight 120 ft., passive Perception 20
Languages Abyssal, Common, telepathy 120 ft.
Challenge 25 (75,000 XP)
Shapechanger. Kukulkan can use its action to polymorph into a Medium yuan-ti of its choice, or back into its true form. Without wings, it loses its flying speed. Other than its size and speed, its statistics are the same in each form. Any equipment it is wearing or carrying isn’t transformed. It reverts to its true form if it dies.
Heated Body. A creature that touches Kukulkan or hits it with a melee attack while within 5 feet of it takes 14 (4d6) fire damage.
Legendary Resistance (2/Day). If Kukulkan fails a saving throw, it can choose to succeed instead.
Magic Resistance. Kukulkan has advantage on saving throws against spells and other magical effects.
Magic Weapons. Kukulkan’s weapon attacks are magical.
Innate Spellcasting. Kukulkan’s spellcasting ability is Charisma (spell save DC 22). Kukulkan can innately cast the following spells, requiring no material components:
1/day each: destructive wave (radiant), sickening radiance, sunbeam, sunburst
Actions
Multiattack. Kukulkan makes three attacks: one with its bite, and two with its claws, one of which can be replaced by a fire spit attack.
Bite. Melee Weapon Attack: +16 to hit, reach 10 ft., one target. Hit: 26 (4d8 + 8) piercing damage plus 14 (4d6) fire damage, and if the target is a creature, it must succeed on a DC 23 Constitution saving throw or take 22 (4d10) poison damage.
Claws. Melee Weapon Attack: +16 to hit, reach 15 ft., one target. Hit: 22 (4d6 + 8) slashing damage plus 7 (2d6) fire damage.
Fire Spit. Ranged Weapon Attack: +11 to hit, range 40/160 ft., one target. Hit: 21 (6d6) fire damage.
Tail. Melee Weapon Attack: +16 to hit, reach 20 ft., one target. Hit: 26 (4d8 + 8) bludgeonign damage, and the target must succeed on a DC 18 Strength saving throw or be knocked prone.
Constrict. Melee Weapon Attack: +16 to hit, reach 5 ft., one creature. Hit: 26 (4d8 + 8) bludgeoning damage, and the target is grappled (escape DC 18). Until this grapple ends, the creature is restrained and subject to Kukulkan's Heated Body trait, and Kukulkan can’t constrict another target.
Swallow. Kukulkan makes one bite attack against a Medium or smaller target. If the attack hits, the target is swallowed. The swallowed target is blinded and restrained, it has total cover against attacks and other effects outside kukulkan, and it takes 14 (4d6) acid damage and 14 (4d6) fire damage at the start of each of Kukulkan’s turns. Kukulkan can have only one target swallowed at a time.
If Kukulkan dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 5 feet of movement, exiting prone.Legendary Actions
Kukulkan can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. Kukulkan regains spent legendary actions at the start of its turn.
Tail. Kukulkan makes one tail attack.
Earth Tremor. Kukulkan slams the ground causing it to quake in a 120-foot radius. Each creature on the ground in this area must succeed on a DC 18 Dexterity saving throw or be knocked prone and be unable to take opportunity attacks until the start of its next turn.
Fire Breath (Costs 2 Actions). Kukulkan exhales fire in a 30-foot cone. Each creature in the area must make a DC 22 Dexterity saving throw, taking 21 (6d6) fire damage on a failed save, or half as much on a successful one.

image source: Bulbapedia
Bewear
Suggested by Patron and Discord regular @griffmac, based on the adorable pokemon.
A construct made of a tough, yet flexible fabric exterior encasing a kind of fluffy, down-like filling, this creature is not too dissimilar to a scarecrow. Its softness in fact makes it surprisingly difficult for its foes to land damaging blows.
Bewear
Medium construct, unaligned
Armor Class 14 (natural armor)
Hit Points 110 (13d8 + 52)
Speed 30 ft.
STR DEX CON INT WIS CHA 18 (+4) 11 (+0) 18 (+4) 3 (-4) 13 (+1) 15 (+2)
Saving Throws Str +7, Con +7, Wis +4
Skills Perception +4
Damage Vulnerabilities fire
Damage Resistances piercing, slashing
Damage Immunities bludgeoning
Condition Immunities charmed, exhaustion, frightened, paralysed, petrified, poisoned, unconscious
Senses darkvision 60 ft., passive Perception 14
Languages understands one language of its creator but can't speak
Challenge 6 (2,300 XP)
Thrash (Recharge 5–6). If the bewear hits a creature with a melee attack, it can begin thrashing. When it does, the bewear can make an additional melee attack against that creature as a bonus action on each of its turns until
the bewear misses the creature with an attack, or ends its turn without attacking that creature. This trait can't recharge while the bewear is thrashing.
Doll Eyes (Recharge 5–6). As a bonus action, the bewear can make an adorable face, attempting to charm each creature in a 30-foot cone. Each creature in the area that can see the bewear must succeed on a DC 15 Wisdom saving throw or be charmed by the bewear for 1 minute. A charmed creature can repeat its save at the end of each of its turns, with advantage if the bewear has attacked it since the beginning of the creature's last turn, ending the charm effect on it on a success. After the charm ends for a creature, that deals half damage to the bewear until the end of its next turn.
Actions
Hammer Arm. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) bludgeoning damage.
Brutal Swing. Melee Weapon Attack: +7 to hit, reach 5 ft., all creatures within reach. Hit: 7 (1d6 + 4) bludgeoning damage.
Payback. As part of this action, the bewear prepares a hammer arm attack against the next creature to hit it with a melee attack. If the action triggers before the start of the bewear's next turn and the hammer arm attack hits, that attack is treated as a critical hit.

Image source: Destiny wikia.
Hive Thralls
Suggested by Patron and Twitch viewer @whistlehunter, based on the enemy from the Destiny series.
Thrall
Medium aberration (hive), lawful evil
Armor Class 13 (natural armor)
Hit Points 19 (3d8 + 6)
Speed 30 ft.
STR DEX CON INT WIS CHA 10 (+0) 15 (+2) 14 (+2) 5 (-3) 9 (-1) 6 (-2)
Skills Acrobatics +4
Damage Immunities poison
Condition Immunities exhaustion, poisoned
Senses blindsight 120 ft. (blind beyond this radius), passive Perception 9
Languages understands Abyssal and Deep Speech but can't speak
Challenge 1 (200 XP)
Dark Devotion. The thrall has advantage on saving throws against being charmed or frightened.
Leaping Charge. If the thrall moves at least 20 feet straight toward a creature and then hits it with a claw attack on the same turn, the target takes an extra 3 (1d6) slashing damage.
Pack Tactics The thrall has advantage on an attack roll against a creature if at least one of the thrall’s allies is within 5 feet of the creature and the ally isn’t incapacitated.
Actions
Multiattack. The thrall makes two attacks with its claws.
Claws. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) slashing damage.

image source: Destinypedia.
Cursed Thrall
Medium aberration (hive), lawful evil
Armor Class 13 (natural armor)
Hit Points 19 (3d8 + 6)
Speed 25 ft.
STR DEX CON INT WIS CHA 10 (+0) 15 (+2) 14 (+2) 5 (-3) 9 (-1) 6 (-2)
Damage Immunities poison
Condition Immunities exhaustion, poisoned
Senses blindsight 120 ft. (blind beyond this radius), passive Perception 9
Languages understands Abyssal and Deep Speech but can't speak
Challenge 2 (450 XP)
Dark Devotion. The thrall has advantage on saving throws against being charmed or frightened.
Death Burst. When the thrall dies, it explodes in a burst of unholy energy. Each creature within 5 feet of it must make a DC 13 Dexterity saving throw, taking 7 (2d6) necrotic damage and 7 (2d6) lightning damage on a failed save, or half as much on a successful one.
Actions
Detonate. The thrall moves up to half of its speed and detonates, killing it and triggering its death burst.