What changed for monsters in the 2024 D&D rules

This compares the mechanical fields — the ones that change how something behaves at the table. It deliberately does not report that the wording changed: the 2024 SRD rewrote almost every spell description into a new format, so “the text is different” is true of nearly everything and tells you nothing.

A field is skipped where either edition leaves it blank, because that is a gap in the source data rather than a change to the game.

Monsters that changed (170)

Compared on: Armour class, Hit points, Challenge rating, Size, Type.

Monster	What	2014	2024
Aboleth	Hit points	135	150
Adult Blue Dragon	Hit points	225	212
Adult Bronze Dragon	Armour class	19	18
Adult Gold Dragon	Hit points	256	243
Adult Silver Dragon	Hit points	243	216
Ancient Brass Dragon	Hit points	297	332
Ancient Copper Dragon	Hit points	350	367
Ancient Green Dragon	Hit points	385	402
Ancient Red Dragon	Hit points	546	507
Ancient Silver Dragon	Hit points	487	468
Ankheg	Hit points	39	45
Archmage	Armour class	12	17
	Hit points	99	170
	Size	Medium	Small
Assassin	Armour class	15	16
	Hit points	78	97
	Size	Medium	Small
Axe Beak	Type	Beast	Monstrosity
Badger	Armour class	10	11
	Hit points	3	5
	Size	Tiny	Small
Balor	Hit points	262	287
Bandit	Size	Medium	Small
Bandit Captain	Hit points	65	52
	Size	Medium	Small
Bat	Size	Tiny	Small
Bearded Devil	Hit points	52	58
Berserker	Size	Medium	Small
Black Pudding	Hit points	85	68
Blue Dragon Wyrmling	Hit points	52	65
Boar	Hit points	11	13
Bone Devil	Armour class	19	16
	Hit points	142	161
Brass Dragon Wyrmling	Armour class	16	15
	Hit points	16	22
Bronze Dragon Wyrmling	Armour class	17	15
	Hit points	32	39
Brown Bear	Hit points	34	22
Camel	Armour class	9	10
	Hit points	15	17
Cat	Size	Tiny	Small
Chain Devil	Armour class	16	15
	Challenge rating	11	8
Chuul	Hit points	93	76
Clay Golem	Hit points	133	123
Cloaker	Hit points	78	91
Cockatrice	Hit points	27	22
Commoner	Size	Medium	Small
Constrictor Snake	Armour class	12	13
Couatl	Hit points	97	60
Crab	Hit points	2	3
	Size	Tiny	Small
Crocodile	Hit points	19	13
Cultist	Size	Medium	Small
Darkmantle	Type	Monstrosity	Aberration
Deva	Hit points	136	229
Dire Wolf	Hit points	37	22
Djinni	Hit points	161	218
Draft Horse	Hit points	19	15
Dragon Turtle	Hit points	341	356
Druid	Armour class	11	13
	Hit points	27	44
	Size	Medium	Small
Dryad	Armour class	11	16
Eagle	Hit points	3	4
Earth Elemental	Hit points	126	147
Efreeti	Hit points	200	212
Elk	Hit points	13	11
Erinyes	Hit points	153	178
Fire Elemental	Hit points	102	93
Flesh Golem	Hit points	93	127
Flying Snake	Size	Tiny	Small
	Type	Beast	Monstrosity
Frog	Size	Tiny	Small
Frost Giant	Hit points	138	149
Gargoyle	Hit points	52	67
Gelatinous Cube	Hit points	84	63
Giant Ape	Hit points	157	168
Giant Badger	Armour class	10	13
	Hit points	13	15
Giant Boar	Armour class	12	13
Giant Centipede	Armour class	13	14
	Hit points	4	9
Giant Eagle	Type	Beast	Celestial
Giant Elk	Armour class	15	14
	Type	Beast	Celestial
Giant Octopus	Hit points	52	45
Giant Owl	Type	Beast	Celestial
Giant Rat	Armour class	12	13
Giant Shark	Hit points	126	92
Giant Vulture	Hit points	22	25
	Type	Beast	Monstrosity
Giant Wasp	Armour class	12	13
	Hit points	13	22
Gibbering Mouther	Hit points	67	52
Glabrezu	Hit points	157	189
Gladiator	Size	Medium	Small
Gorgon	Type	Monstrosity	Construct
Gray Ooze	Armour class	8	9
Grick	Hit points	27	54
	Type	Monstrosity	Aberration
Grimlock	Type	Humanoid	Aberration
Guard	Size	Medium	Small
Guardian Naga	Hit points	127	136
	Type	Monstrosity	Celestial
Hawk	Size	Tiny	Small
Hell Hound	Hit points	45	58
Hezrou	Armour class	16	18
	Hit points	136	157
Hippogriff	Hit points	19	26
Homunculus	Hit points	5	4
	Size	Tiny	Small
Horned Devil	Hit points	178	199
Hydra	Hit points	172	184
Ice Devil	Hit points	180	228
Imp	Hit points	10	21
	Size	Tiny	Small
Invisible Stalker	Hit points	104	97
	Size	Medium	Large
Iron Golem	Hit points	210	252
Knight	Size	Medium	Small
Kraken	Hit points	472	481
Lamia	Type	Monstrosity	Fiend
Lemure	Armour class	7	9
	Hit points	13	9
Lich	Armour class	17	20
	Hit points	135	315
Lion	Hit points	26	22
Lizard	Size	Tiny	Small
Mage	Armour class	12	15
	Hit points	40	81
	Size	Medium	Small
Magma Mephit	Hit points	22	18
Magmin	Hit points	9	13
Marilith	Armour class	18	16
	Hit points	189	220
Minotaur Skeleton	Hit points	67	45
Mummy	Size	Medium	Small
Mummy Lord	Hit points	97	187
	Size	Medium	Small
Noble	Size	Medium	Small
Ochre Jelly	Hit points	45	52
Ogre	Hit points	59	68
Oni	Armour class	16	17
	Hit points	110	119
	Type	Giant	Fiend
Otyugh	Hit points	114	104
Owl	Size	Tiny	Small
Panther	Armour class	12	13
Phase Spider	Armour class	13	14
	Hit points	32	45
Pit Fiend	Armour class	19	21
	Hit points	300	337
Planetar	Hit points	200	262
Priest	Hit points	27	38
	Size	Medium	Small
Pseudodragon	Armour class	13	14
	Hit points	7	10
	Size	Tiny	Small
Quasit	Hit points	7	25
	Size	Tiny	Small
Rakshasa	Armour class	16	17
	Hit points	110	221
Rat	Size	Tiny	Small
Raven	Hit points	1	2
	Size	Tiny	Small
Rhinoceros	Armour class	11	13
Riding Horse	Armour class	10	11
Roper	Type	Monstrosity	Aberration
Rust Monster	Hit points	27	33
Saber-Toothed Tiger	Armour class	12	13
Satyr	Armour class	14	13
Scorpion	Size	Tiny	Small
Scout	Size	Medium	Small
Shadow	Hit points	16	27
Shambling Mound	Hit points	136	110
Skeleton	Armour class	13	14
Solar	Hit points	243	297
Spider	Size	Tiny	Small
Spirit Naga	Armour class	15	17
	Hit points	75	135
	Type	Monstrosity	Fiend
Sprite	Hit points	2	10
	Size	Tiny	Small
Spy	Size	Medium	Small
Steam Mephit	Hit points	21	17
Stirge	Armour class	14	13
	Hit points	2	5
	Size	Tiny	Small
	Type	Beast	Monstrosity
Stone Golem	Armour class	17	18
	Hit points	178	220
Swarm of Bats	Hit points	22	11
	Size	Medium	Large
Swarm of Insects	Armour class	12	11
	Hit points	22	19
Swarm of Rats	Hit points	24	14
Swarm of Ravens	Hit points	24	11
Tarrasque	Hit points	676	697
Tiger	Armour class	12	13
	Hit points	37	30
Triceratops	Armour class	13	14
	Hit points	95	114
Troll	Hit points	84	94
Unicorn	Hit points	67	97
Vampire	Hit points	144	195
	Size	Medium	Small
Vampire Spawn	Armour class	15	16
	Hit points	82	90
	Size	Medium	Small
Vrock	Hit points	104	152
Weasel	Size	Tiny	Small
Werebear	Armour class	10	15
	Size	Medium	Small
	Type	Humanoid	Monstrosity
Wereboar	Armour class	10	15
	Hit points	78	97
	Size	Medium	Small
	Type	Humanoid	Monstrosity
Wererat	Armour class	12	13
	Hit points	33	60
	Size	Medium	Small
	Type	Humanoid	Monstrosity
Weretiger	Size	Medium	Small
	Type	Humanoid	Monstrosity
Werewolf	Armour class	11	15
	Hit points	58	71
	Size	Medium	Small
	Type	Humanoid	Monstrosity
Wight	Hit points	45	82
Will-o'-Wisp	Hit points	22	27
	Size	Tiny	Small
Wolf	Armour class	13	12
Worg	Type	Monstrosity	Fey
Wraith	Size	Medium	Small
Wyvern	Armour class	13	14
	Hit points	110	127
Xorn	Hit points	73	84
Young Bronze Dragon	Armour class	18	17
Young White Dragon	Hit points	133	123
Zombie	Hit points	22	15

New in 2024 (48)

In 2014 but not 2024 (42)

Absent from the 2024 SRD. That is not the same as removed from the game — the SRD is a subset of what the books publish.