Through really tiny stitches, you alter the physiology of your subjec– er… companions, in an unending quest for perfection. Many Splicers delve into the world of adventuring in the hopes of discovering exciting new improvements with which to augment their companions. Your foray into the world of biomancy, whether through wizarding school, working with biosmith artificers, or as the surgical assistant to a mad scientist, has resulted in a singular observation: subjects are much more malleable when they’re psychically bonded to you.

3rd-level Splicer feature
You can fiddle with the very essence of your companions, crafting minor improvements and modifications. When you choose this paradigm, you gain 3 splicer points. Each time you gain a level in the tamer class, you gain 1 additional splicer point. You can spend these points to modify your companions with the following augments—features and traits that take effect when you next finish a long rest. Splicer points are shared across all your companions. If a companion is ever released, it loses any augments it had and the splicer points are refunded. Augments can be gained only once unless otherwise stated. See the Splicer Augments table on the next page for more details.

Surgeon’s Tools. You also gain proficiency with surgeon’s tools (see page 121). You can spend 1 hour removing all augments from one companion with your surgeon’s tools, causing it to lose all the associated effects. You regain all splicer points spent on that companion and can re-allocate those points as you see fit

3rd-level Splicer feature
You learn additional spells when you reach certain levels in this class, as shown in the Splicer Spells table. Each spell counts as a tamer spell for you, but it doesn’t count against the number of tamer spells you know.

7th-level Splicer feature
You can upgrade each of your companions with exotic organs and appendages. At the start of a long rest, you can choose one of the following upgrades for each of your companions. At the end of the long rest, the biomantic meld completes, and your companion gains the associated action option. The DC for the saving throw equals your tamer spell save DC.

Once a companion uses one of these actions, it can’t do so again until it finishes a short or long rest. Starting at 18th level, a companion can use this action twice before a rest.

10th-level Splicer feature
You augment your companions with a highly adaptive mutagen, allowing them to gain the strengths of foes they defeat and confer it to your other companions through a synchronous quantum biomantic link. As an action, you can command your companion to consume the corpse of a non-swarm creature that has been dead for less than 1 minute. Choose one of the consumed creature’s damage resistances, damage immunities, or condition immunities (except immunity to exhaustion). All of your companions gain resistance to one damage type to which the slain creature was resistant or immune, or gain immunity to one condition to which the creature was immune.

After you use this feature, you can’t do so again until you finish a long rest. When you use this feature again, your companions lose any benefit they had previously gained from this feature.

14th-level Splicer feature
As an action, you trigger a hidden, internal switch within your companion, triggering a cascade of rapid mutations that lasts for the next minute, with the following results:

The creature can breathe only underwater.

The creature can breathe air and water.

The creature gains darkvision out to 60 feet. If it already has darkvision, the range is increased by 60 feet up to a maximum of 120 feet.

The creature gains an additional limb, allowing it to have one additional target grappled. A creature can gain a total of four extra limbs from this augment.

The creature gains a swimming speed of 30 feet. If it already has a slower swimming speed, this speed is increased to 30 feet.

The creature sheds bright light in a 10-foot radius and dim light for an additional 10 feet.

The creature has advantage on Wisdom (Perception) checks that rely on hearing.

The creature has advantage on Wisdom (Perception) checks that rely on sight.

The creature has advantage on Wisdom (Perception) checks that rely on smell.

The creature counts as one size larger when determining its carrying capacity and the weight it can push, drag, or lift.

The creature gains a climbing speed of 30 feet. If it already has a slower climbing speed, this speed is increased to 30 feet.

The creature has advantage on ability checks and saving throws made to escape a grapple.

The creature has advantage on Strength and Dexterity saving throws made against effects that would knock it prone.

While in contact with a web, the creature knows the exact location of any other creature in contact with the same web. The creature ignores movement restrictions caused by webbing.

The creature gains a burrowing speed of 15 feet. If it already has a slower burrowing speed, this speed is increased to 15 feet. It does not leave an opening behind it while burrowing.

When the creature makes a melee attack on its turn, its reach for it is 5 feet greater than normal.

The creature can mimic simple sounds it has heard, such as a person whispering, a baby crying, or an animal chittering. A creature that hears the sounds can tell they are imitations with a successful Wisdom (Insight) check. The DC equals 8 plus your proficiency bonus.

The creature gains a +1 bonus to its AC. It can take this augment a maximum of 3 times, gaining an additional +1 bonus each time.

The first time the creature hits with a weapon attack on its turn, it deals an additional 1d4 poison damage. A creature can take this augment again at 9th level, increasing the bonus to 2d4 poison damage. While a creature has this augment, it can’t take the Corrosive Touch or Decaying Touch augments.

The creature can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

The creature has advantage on Dexterity (Stealth) checks made while not moving.

The first time the creature hits with a weapon attack on its turn, it deals an additional 1d6 acid damage. A creature can take this augment again at 13th level, increasing the bonus to 2d6 acid damage. While a creature has this augment, it can’t take the Poisonous Touch or Decaying Touch augments.

The creature gains tremorsense out to 15 feet. If it already has tremorsense, the range is increased by 15 feet up to a maximum of 30 feet. A creature with tremorsense can detect and pinpoint the origin of vibrations within a specific radius, provided that the monster and the source of the vibrations are in contact with the same ground or substance. Tremorsense can’t be used to detect flying or incorporeal creatures.

The creature gains a flying speed of 30 feet. If it already has a slower flying speed, this speed is increased to 30 feet.

The creature gains blindsight out to 15 feet. If it already has blindsight, the range is increased by 15 feet up to a maximum of 30 feet. A creature with blindsight can perceive its surroundings without relying on sight, within a specific radius. The creature can’t use its blindsight while deafened.

The first time the creature hits with a weapon attack on its turn, it deals an additional 1d8 necrotic damage. A creature can take this augment again at 17th level, increasing the bonus to 2d8 necrotic damage. While a creature has this augment, it can’t take the Poisonous Touch or Corrosive Touch augments.

The creature doesn’t provoke opportunity attacks when it flies out of an enemy’s reach.

The creature’s size is increased by one category. In addition, the size of its Hit Die is increased by 1; add 1 to the creature’s maximum hit points for each Hit Die it has when it gains this augment. Note, this augment can be taken multiple times but can’t increase a companion’s size beyond that permitted by your tamer level (see Tamer Companion Summary table, page 198).