Homebrew Parasect Slime Mushroom Symbiote Species Details

Parasites are born in darkness, silence and isolation, their birth becoming devoid of warmth and education. As such, all parasites have a desire to learn and explore the world beyond the hole they hatched in, all in the hope of finding a connection with other creatures. Parasites are immortal beings, which gives them a myriad of life experiences and plenty of time for introspection. Yet, they do not understand why they were brought into this world just to hop from creature to creature and live out an infinite amount of lives. It is this feeling of nihilism that drives them towards adventuring, as perhaps in this vast world, they can finally find the meaning they so desire.
You are big for the microbe universe, but too small for the material plane to acknowledge your existence. You act similar to a virus or bacterium and attack the host nervous system.
Furthermore, you can cure a willing host or drain the life essence of the host through the use of the microbial world. Your Species are known to enslave, or help evolve life by maintain knowledge and sharing knowledge to and from hosts.

Symbiotic Form:

When outside a host, you have the following base stats:
Base Stats: Str 10 / Dex 10 / Con 10 / Int 10 / Wis 10 / Cha 10
Tiny Aberration
Armor Class 10
Hit Points 10 (4d4)
Speed 5 ft. (Climb, Swim, Walk)
Advanced Vision: You are able to perceive the world as if you had normal, low light, and dark vision. You are also able to see body heat. You host can't gain the same vision.
Furthermore, you can’t exist outside a host for more than 10 days. You can enter a dead body less than 24 hours at stage 1 and within 2 day at stage 3. They are not considered undead, see Reborn/Reanimated. You must vacate the dead host with in 24 days due to decomposing elements, unless you eat food stuffs within 24 hours, otherwise you eat away of the body and look more skeletal in design.

Hostile Takeover

As an action, whether inside or outside your Permanent Host, you may attempt to take possession of another creature within 5ft, latching on to their body and becoming intertwined with their biology. You are still subject to individual targeting if below stage 2, despite occupying the same space. You may only activate this ability if the new Host is of a challenge rating equal to or lower of that you are able to access, as shown in The Parasite Table.

(DM Discretion) Normal = Creatures you can access up to Stage 3
(DM Discretion) Greater = Creatures you can access up to Stage 2
(DM Discretion) Superior = Creatures you can access up to Stage 1.

When you activate this ability, you may make a Constitution roll against the target’s Constitution stat, adding your Constitution Modifier + Proficiency Bonus to the roll. If you succeed, you go to Stage 1; if you fail, you do not latch on to the creature and land next to it.
You can be forcefully removed(DC12) At stage 0,(Medicine/Nature check). At stage 1,(Medicine/Nature check and constitution check. At stage 2 and above, Divine Intervention.

Stage 0 = You are passively living on the creature. This is only available if done through Stealth, or the target is friendly.
Stage 1 = You have infected the target’s nervous system. Every time the creature attempts to make an action or move on its turn, you may use your reaction to force it to make a Wisdom saving throw against your DC. If the target fails, its action is wasted.
Stage 2 = You have taken full control of the target’s body. As an action, you may use one of the creature’s available actions as though you were the creature. As a move action, you may move as though you were the creature. The creature may use its reaction to make a Wisdom saving throw against your DC
Stage 3 = You have taken complete control of the target’s mind. This creature is now your Permanent Host.
Stage 4 = The host has given up on trying to return to its body and relinquishes control. 

If the Creature is unconscious they roll at disadvantage. The creature may spend an action to make a Strength check to attempt to force you down one stage (Stage 0 does not count for the purpose of this interaction). If the creature fails, you do not go up a Stage. As an action, you may use this feature again to go up another stage, following the same rules. If you fail, you do not go down one Stage. When you reach Stage 3 and the creature becomes your Permanent Host, it does not regain any lost Hit Points.

Your DC = 8 + Constitution Modifier + Proficiency Bonus

Level	Hostile Takeover CR Limit (Normal, Greater, Superior)
1st	1/8, 1/4, 1/2
2nd	1/8, 1/4, 1/2
3rd	1/8, 1/4, 1/2
4th	1/8, 1/4, 1/2
5th	1, 2, 3
6th	1, 2, 3
7th	1, 2, 3
8th	1, 2, 3
9th	2, 4, 6
10th	2, 4, 6
11th	2, 4, 6
12th	2, 4, 6
13th	3, 6, 9
14th	3, 6, 9
15th	3, 6, 9
16th	3, 6, 9
17th	4, 8, 12
18th	4, 8, 12
19th	4, 8, 12
20th	5, 10, 15

*You can expend a Parasitic Die to go up a stage without incurring a check, only after stage 0 and can't be used to reach the last stage following CR and DM Digression...

Parasitic Die:

Use your Parasite's Hit Die pool as special die for the use of maintaining control over the host, regaining HP, or to use special actions. You gain an additional HD 1 per Total Class level. During a short rest, if you are stage 1 or above, you can attempt to steal a single HD from your host. Once every short rest, you can expend 1HD to give your host a Temporary HD from their Hit Dice Pool. As a bonus action, you may regain HP equal to 1HD + Constitution Modifier + Your Total Class Level. This consumes the HD. If you have 0 Hit Die while at stage 3 you are considered exhausted and attempt to steal an HD from your host immediately, when this occurs the host can attempt to expel you dropping you a stage (Strength and Constitution check You have advantage), you regain 1 HD regardless and recover from exhaustion. If you have 0 Hit Die and in your symbiotic form you are considered Restrained, Blinded, Deafened, but can still see body heat.

Permanent Host (Stage 3)

You have made a bond with a creature. Choose a creature of challenge rating 1/8th or lower. This creature becomes your starting Host. You gain access to all of its features, abilities, skills, proficiencies, languages, equipment, AC and speed, which are added on top of whatever you already have. You are able to infuse your knowledge with a creature as you replace body parts you grant them your knowledge and take their knowledge with you. Furthermore, you replace the host class with your own. You gain access to the creature’s stats, adding the modifier of your natural stats to your host’s stats. You may go above 20. Furthermore, you use your proficiency bonus instead of the creatures. You gain access to your Host’s HP and Hit Die separately, but combine them for combat game mechanics. If you are reduced to 0 Hit Points while within your Permanent Host, your Host dies, but you leave with Max HP.
If you leave your Host, it falls unconscious and dies in 1 hour unless treated with a Heal spell or greater, as when you make a bond with a creature, you have replaced its vital organs. If your Host dies with you still inside, you immediately leave its body and revert to your Symbiotic form. If you have no Permanent Host, you retain nothing you previously had access to while inside one. Your Host does not gain Hit Points from Hit Dice spent during short rests. You are treated like a supernatural disease for the purpose of game mechanics. You may only take over a host a number of times equal to your proficiency bonus per long rest.

Preferred Host

Starting at 3rd level, you have found yourself bonding with a particular type of creature more than others. Choose a type of creature:

Aberrations, Beasts, Celestials, Constructs, Dragons, Elementals, Fey, Fiends, Humanoids, Giants, Monstrosities, Oozes, Plants, Undead

You may add 1d4 to any saving throw, skill check or damage roll that involves this creature at the expense of the Parasitic HD. You choose one additional Preferred Host at 6th, 9th, 12th, and 18th level.

Consume The Weak

Starting at 5th level, you have become more proficient in taking control of creatures’ minds, to the point where lesser beings can no longer resist against your Hostile Takeover. You may immediately go to Stage 2 when attempting a Hostile Takeover of a creature of half of the CR of Normal creatures, rounded down (Lesser); and Stage 3 for those that are a quarter of Normal creatures, rounded down (Inferior). If you fail to latch on, you automatically go down to the Stage below what you attempted to access.

Undying Substance

Starting at 10th level, your natural body has become more adept at surviving outside a Host, becoming stickier and more elastic to allow you to slip out of death more easily. If you drop to 0 HP, you may make a DC10 Constitution saving throw, which increases by 5 each time you use it. If you succeed, you drop to 1 HP and regain all of your Parasitic HD (14). The Save DC is reset to 10 at the end of a long rest.

Parasect Slime Mushroom Symbiote Traits

Symbiotic Form, Parasitic Die, Hostile Takeover, Permanent Host, Preferred Host, Consume The Weak, Undying Substance

Abitlity Scores(Tasha)

As you leave and infect hosts, you take and impasse some knowledge. add 1 to any score 3 times. You bestow your knowledge of magic and keep feats you have deemed necessary for host survivals.

Maintain Language and Class

Due to your age, you are able to speak and communicate in any language your host original had access to, you can also use your host to speak other languages you previously inhabited.