Shadow Symbiont (3.5e Monster)

''You see a small patch of slightly deeper darkness floating across the floor. Your leg feels cold as it climbs up, but strangely, you feel no fear.''

These parasites originated on the plane of shadow, but have since spread out through their hosts. They don't naturally occur on their own anywhere but the plane of Shadow, though. While quite weak on its own, it tries to bond to a willing host, granting the host multiple powers at its own leisure. It rarely leaves it's bonded host's body while on the material plane, rather like a 3 year old child not leaving it's mother. Whenever the host gains a level, thry may opt to let the shadow parasite grow by one size category but take a cumulative -1 penalty to constitution.

Combat
It doesn't usually attack on its own, instead augmenting the abilities of its host. While bonded, it is in the parasite's best interest to keep it's host alive. It has several abilities, and it chooses one every turn. When bonded over a larger period of time, the parasite learns to cooperate better with the host. Over time, the parasite also grows stronger, resulting in higher bonusses for the host.

Attach : A shadow parasite can attach to any willing creature. The parasite attempts to embrace its target, and with a successful melee touch attack, the parasite is attached to the target. A target who spends a full-round action can break free of the embrace and move up to half its speed away from the parasite if desired, but can do nothing else. An attached ooze nestles itself in and on the target's skin, able to hide itself completely if so desired without added stress on the host.

Parasitic bond : When attached, the parasite settles down on the host's body. It draws sustenance from the host's body, resulting in a -1 penalty on constitution while the parasite is so attached.

Split : A parasite of at least medium size may split up into (1 + 1 per size category above tiny) tiny oozes, all of which are exactly the same as the original. It may also branch off tiny parasites, thereby shrinking one size catagory itself and thus giving one less constitution penalty. The new parasites may or may not remain attached to the wearer, either incurring their own penalty on constitution or not. Please note that the total amount of constitution "drain" remains the same. Multiple parasites attached to the same host get to act independently.

Defend Host : The parasite can offer a bonus to armor class equal to 2 (+1 per size catagory above tiny).

Mask Host : While bonded, a parasite of at least tiny size can cover the host's face. This results in a +2 penalty on any spot check made to recognize the host, and a +1 bonus to saves against spells with the "light" descriptor. Additionally, it functions like sunglasses.

Pseudopod Strike : While bonded, the parasite can lash out with a pseudopod, dealing 1d2 bludgeoning damage + 2 cold damage. This grows with size as appropriate.

Augment Stealth : While bonded, a parasite of at least small size can augment the host's stealth, by blending the host and the background. This offers a +(3 +1 per size catagory above small) bonus to Hide checks.

Augment Reach : While bonded, a parasite of at least small size can augment the host's reach, by timing its Pseudopod Strike in time with the host's attack. This gives the attack a reach of 10ft, while still being able to deal damage to creatures nearer than that. The damage dealt is equal to the amount and type of damage dealt with the parasite's pseudopod Strike. This ability cannot be used in conjunction with any weapon, as the ooze cannot wield one.

Engulf : While bonded, a parasite of at least medium size can completely engulf it's host if its the same size category or smaller. This results in a +2 bonus to strenghth and AC, fire resistance 5, and a +4 bonus on any save against a spell with the light description.

Shadow Tentacle : While bonded, a parasite of at least medium size can engulf its host's arm, giving him a +2 bonus on strength and a reach of 10 feet, acting like an extension of the host's arm (useful beyond combat). This allows the host to grab things too far away to reach normally or to use his shadowy arm to swing down from a balcony and land savely on the ground, for example.