Bairns are the infected version of various baby mobs, belonging in the Combat Abnormal tier (though, their entity class extends them to the Infected tier). They're small and quick melee combatants.
Spawning
Converted from a baby Zombie, Husk, Drowned, Villager, or Zombie Villager if it dies with Mycelium Infection.
Spawned from a Swarmer Howler Variant's howl in groups of 4 to 7.
Unique Behavior
When finding a container within a 20x4x20 block area that has food items in it, Bairns will run up to it and eat the food inside. When eating the food, for each item they eat, they gain 1 kill point. Once the container has run out of food, the Bairn will break the container.
Every 5 seconds, Bairns will search for any Hexenmeister Claws in a 26 block range. If finding one, they will move towards it and start riding it, resulting in a Claw Jockey.
Their hits reset their target's immunity frames, meaning they can hit you faster than mobs that don't reset I-frames.
Bairns often pounce at their targets when in close range. They can utilize this to leap across small gaps to reach targets.
Variants
Bairns have an 80% chance to spawn as one of their four Variants (excluding normal Bairns) when spawned via Swarmer Howler Variants, spawn eggs, commands, etc., with an overall 20% chance per Variant. When spawned via converted baby mobs, a Bairn's Variant depends on which baby mob the Bairn was converted from.
Husk Bairns spawn from baby Husks. They inflict Hunger I for 1 minute when dealing melee damage.
Drowned Bairns spawn from baby Drowned. They are aquatic; they can breathe underwater and swim fast in liquids.
Villager Bairns spawn from baby Villagers. They are capable of opening Wooden Doors if in the way in order to pathfind.
Diseased Villager Bairns spawn from baby Zombie Villagers. They inflict Poison I and Nausea I for 10 seconds when dealing melee damage. Additionally, they are capable of opening Wooden Doors if in the way in order to pathfind.
Behavior
Bairns are hostile to most non-Spore mobs, with the exceptions being Animals and Fish (unless Should attack Animals is enabled via the Config) and mobs included in the Mobs Not Targeted blacklist within the Config.
Bairns inflict Mycelium Infection I for 30 seconds when dealing melee damage.
Can perform short dashes in liquids to pursue a target.
Bairns have a 5% chance to drop a Scent upon death unless they are freezing.
Bairns can fall victim to Starvation.
Able to utilize Kill Points to grant themselves buffs.
Present a weakness to the cold.
Bairns are influenced by Horde Mentality; they attempt to pair up with Infected, Evolved, Hyper Evolved, Experiments, other Bairns, Scampers, Gastgebers, and Calamities.
Infected can be Linked.
Are affected by the Despawning System.
Are affected by Vanilla Despawning (unless they have any Evolution Points).
In regards to Frostbite, have a Body Heat of 1 and Enum Percentage of 10%.
Related Advancements
Drops
Claw Fragment (80% chance for 1 - 3)
Mutated Fibre (80% chance for 1 - 5)
Mutated Heart (10% chance for 1)
Lore
To make the baby mobs large and bulky enough to be competent infectors, the fungus took advantage of the child's partially underdeveloped form to begin a very rapid and imperfect violent puberty. Due to this sudden burst of growth, it makes the creature not only a little awkward on its feet, but also insatiably ravenous, as it has burned what little fat and energy it had stored in order to achieve the flawed acceleration of its host's forced puberty.
Bairn
Statistics
HP: 12 (x6 hearts)
Armor: 1 (x0.5 bars)
Melee Damage: 4 (x2 hearts)
Follow Range: 16 blocks
Move Speed: 0.22
ID: spore:bairn
Threat Level: Low
Trivia
The Bairn is a suggested mob, coming from the mind of @slasherwolf_ in the Spore Asylum Discord server.
The Bairn's model was created by the same person who suggested it, Slasher.
The term 'bairn' in real life means "a child."
Before the Bairn was added, infectable baby mobs would just turn into regular adult Infected forms.
Bairns were meant to latch onto their target's face, but as the mod creator worked on it, he decided it looked too funny so it was scrapped.
Another scrapped ability of the Bairn is that it would've been able to squeeze itself through none-full blocks (fences, slabs, etc.). This was ultimately scrapped due to how broad of blocks Bairns would be able to go through, and selecting specific blocks wouldn't have been broad enough. The mod creator also decided it would've been boring.
Bairns, when eating food from containers, were meant to throw out random non-food items from the container. It's unknown why this was scrapped, but likely because it would've been very annoying if a player's items despawned because of a Bairn.
Despite being in the Abnormal tier, the entity class of the Bairn extends them to the Infected tier.
The Villager Bairn variant had the most thought behind its design. "I wanted to go for a more sad, gross, disturbing vibe. It's the only one with blood, which I added around its body and also made it crying some. Its scarla (the white part of your eye) is a little red, like it's puffy with infection. And it has also vomited up on itself. I wanted said vibe because unlike the other babies who are undead, the villager is alive. It's a turned kid, it should be sad to look at. Like when you see roadkill, it's sad but also gross." (edited quote from Slasher regarding the Bairn Villager variant and his thought process when modeling it).
Gallery
A Claw Jockey with a normal Bairn.
A picture posted in the Discord server teasing the Bairn, Swarmer Howler Variant, Forlorn Howler Variant, and Vanguard before they were released.
A picture posted in the Discord server teasing the Bairn before it was released.
Getting the Bairn to render in-game.
Getting the Bairn to ride Hexenmeister Claws.
Ditto.