The third Darkwood mini-boss, a burrowing Bobbit Worm whose entire fight is decided by one tell.
Barbatos hands you a tell, and the entire fight comes down to reading it. The burrowing worm either spits a harmless spray of projectiles or fires a ring of spikes, and a glance at its base tells you which is coming.
It is the third mini-boss of Darkwood, the first Crusade region. Per the wiki, Barbatos is a Bobbit Worm aligned with the Old Faith, the last of the three Darkwood lieutenants the Lamb clears before facing Leshy.
Like its master, it spends the fight underground. According to the wiki it submerges and burrows between every attack, staying invulnerable and dealing contact damage while buried, so it plays like a smaller, simpler version of the Leshy fight.
This guide covers who Barbatos is, the Darkwood encounter, its burrow-and-spit moveset, the green-pustule tell that wins the fight, how to recruit it as a follower, and where it sits among the Darkwood mini-bosses.
A burrowing Bobbit Worm that alternates spit and spike attacks between dives.
Darkwood, the first Crusade region, as the third mini-boss before Leshy.
Watch its base. Green pustules mean a harmless spit attack you can stand next to and punish.
Recruit it. Like the other Darkwood mini-bosses, a defeated Barbatos joins the cult as a follower.Barbatos is the third mini-boss of Darkwood. Per the wiki it is a Bobbit Worm aligned with the Old Faith, one of the lieutenants serving 
Leshy, the Bishop of Darkwood.
The name is pulled from demonology. According to the wiki, Barbatos comes from the Ars Goetia in the Lesser Key of Solomon, where Barbatos is listed as an Earl and Duke of Hell who can guide people to hidden treasures. All three Darkwood mini-bosses take their names from that same grimoire.
It has three appearances across the fight and the cult. The wiki lists a Boss form, a Boss II form for repeat encounters, and a Follower form for after the Lamb indoctrinates it, since Barbatos is one of the recruitable Darkwood lieutenants rather than a permanent enemy.
Barbatos appears as a mini-boss in Darkwood, the first of the four Crusade regions. Per the wiki it is the third of the three Darkwood mini-bosses, so it shows up later in the region than Amdusias and Valefar and is the final lieutenant before the Leshy boss fight.
The arena is a standard mini-boss room. Clearing it ends that Crusade run, and like the other Darkwood lieutenants, a defeated Barbatos can be carried home and turned into a follower for the cult.
It is an early-game fight, so the stakes are low compared to a Bishop. The value here is the worm itself; recruiting Barbatos adds a Bobbit Worm to the cult roster, and learning its single tell makes the rematches in later runs effectively free.
Barbatos has two attacks, arguably three, and burrows between every one. Per the wiki it submerges and digs to a new location after each attack, and while underground it is invulnerable and damages the Lamb on contact, exactly like the Leshy fight in miniature.
When it surfaces, it does one of two things. According to the wiki it either spits airborne projectiles across the whole arena or shoots out rows of spikes in eight directions around itself.
The two attacks are not random; the worm tells you which is coming. The wiki specifies that green pustules building up at its base during the wind-up mean a spit attack, and the absence of those pustules means a spike attack instead.
The pustules are the whole fight. If green pustules swell at the base of Barbatos, it is winding up the harmless spit; step in and attack. If there are no pustules, it is a spike attack, so back off and wait. Reading that one tell turns Barbatos into a free kill.
Beat Barbatos by punishing every spit attack and disengaging from every spike attack. Per the wiki the method is simple: when it charges a spit, stand next to it and hit it, because the spit is unaimed and easy to dodge even at point-blank range.
Any melee weapon (the spit window lets you trade hits safely up close) Green pustules = attack (no pustules means a spike attack, so disengage)
Make distance (gain space and wait for the next spit instead) Never chase (it is invulnerable underground and damages you on contact)According to the wiki, if Barbatos charges a spike attack instead, the advised play is to gain some distance and simply wait for the next spit attack rather than forcing damage. There is no rush; the worm cycles back to a punishable spit quickly.
That patience is the entire skill check. After a few runs the pattern is automatic: read the pustules, punish the spit, respect the spikes, and never swing at a burrowing worm. Barbatos is one of the most forgiving fights in Darkwood once the tell clicks.
Barbatos is the last of three Darkwood mini-bosses, all named after Ars Goetia demons and all recruitable. Together they are the lieutenants standing between the Lamb and the Bishop of Darkwood.
The other two come first. 
Amdusias is the first mini-boss and spawns Chaser Worms, while 
Valefar is the second. Barbatos closes the trio before Leshy himself.
All three answer to the same master and share the Old Faith allegiance until the Lamb turns them. For the complete picture of how these lieutenants feed into the Bishop fights, see every 
Cult of the Lamb boss in one place.
Barbatos is one of three Darkwood lieutenants. These guides cover the weapons, the Bishops they serve, and the rest of the roster.
Game data and screenshots adapted from cult-of-the-lamb.fandom.com, used under CC BY-SA 3.0. Original content remains the property of the wiki contributors and Massive Monster and Devolver Digital.