Race name: Oozemen

Racial traits:
1) Ability score. +3 Constitution, +1 Dexterity, -1 Intelligence, -1 Wisdom.
2) Age. The oldest Oozemen are said to be as old as 1000 years old. However, due to their genetics and life style most of Oozemen don't live pass 70 years mark.
3) Alignment. Typically Chaotic Neutral. Oozemen individuals do not comprehend morality of other mortal race and thus usually do not view things or people as good or evil. However, in recent time Oozemen started worshiping god and parts of their society started to diverge towards good and evil.
4) Size. Typically medium size. However, in times of need an Oozemen can expand to a large size or compress to a small size.
5) Speed. Same as in humans, however, Oozemen can walk on vertical surfaces and on the ceiling at half of their normal speed.
6) Language. Can speak Common, Elvish, and Primordial.
7) Darkvision. You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can't discern color in darkness, only shades of gray.
8) Heatvision. You can sense heat within 60 feet of you, but you can not differentiate sources of heat.
9) Adapted to the Extremes. Have proficiency in Grappler and Survival skills.
10) Acid Immunity.
11) Underwater Survival. You can breathe in air and in water, and you have a swimming speed equal to your walking speed.
12) Extendable Arms. Your unarmed attack reach is increased by 10 feet. Your armed attack reach in increased by 5 feet.
13) No Bone Structure. You can not equip heavy armor or use two-handed weapons.
14) Bouncy Shock Absorption. You take no damage and can not be killed from falling or things being thrown on you (boulders, etc). Add +4 to your AC while wearing armor. If you wear no armor, then your AC is 6 +Your Dexterity modifier.
15) Consume and Absorb. Can be used at will against any creature in melee range of your attacks. Deal 2d10 Acid damage. You target must make Constitution Saving Throw, and if they fail, then you heal yourself for 100% of damage done. If this ability kills a creature, then inherit that creature's ability to speak any language the creature could speak. After being used this ability can only be used against after completing a short or a long rest.
16) Diverse Slime Shell. Choose one of these origins for your slime body:
* Abyss Slime - whenever you take necrotic or fire damage, then enter into state of regeneration and regenerate 10% of your missing health (rounded down) every turn for 3 turns. During a short or a long rest you can replicate a simple weapon you have seen; this replica weight nothing, but it can not be given to others or dropped. Bonus ability scores: +1 Charisma, -1 Strength.
* Emerald Slime - whenever you take bludgeon damage or get poisoned/diseased, then enter into state of regeneration and regenerate 10% of your missing health (rounded down) every turn for 3 turns. If you spend at least 1 short or long rest in the direct sunlight then you will not need to drink or eat that day. Bonus ability scores: +1 Constitution, -1 Dexterity.
* Golden Slime - whenever you take radiant damage or get healed by an ally, then enter into state of regeneration and regenerate 20% of your missing health (rounded up) every turn for 3 turns. Bonus ability scores: +1 Strength, +1 Constitution, -2 Intellect.
* Ruby Slime - whenever you take fire damage, resists/evade any spell or get affected by any hostile illusion spell, then enter into state of regeneration and regenerate 10% of your missing health (rounded down) every turn for 3 turns. Also gain Arcana skill. Bonus ability scores:  +1 Intellect, +1 wisdom, -2 Constitution.

Backstory.
Long ago a group of Elvish wizard experimented with all sorts of creatures and all sorts of magic. Their experiments were mostly unsuccessful, however, a side effect of those experiments were creation of new kind of slime cells who possessed qualities nerve cells and thus formed into networks within slime bodies. These cells were slime cells in origin, however, they could form cores and take over other slime cells thus acting as some sort of sentient parasite. Over time a new breed of slime formed who all possessed core of of those sentient cells. These slime were sentient and they molded their bodies into shapes similar to their Elven creators.
However, all of this happened long time ago in an Elven Dungeon. When wizards passed away, then their sentient slime creations were left behind to roam underground and attempt to survive. Over time these slime formed their own civilization and started calling each other as Oozemen. Though, they do not possess actual names, so instead they refer to themselves in strings of numbers (example: 21215, 11111 or 53215), because that's how their Elven creators used to refer to them.

Biology.
Slime body of Oozemen are often not to body were born with. Their actual bodies are brain-like cores who control their outer slime bodies. These cores can be transplanted from one non-sentient slime body to another. Any slime creature implanted with the core get taken over by the core and forms into humanoid-like form to serve the core to the best of its abilities.
Outer bodies, also called as shells, live as long as their normal life span, however, cores can live for far much longer, thus periodic transplantations of the core must be done in order for the core to live for its maximum amount of time, though, it is rarely done.
Oozemen typically do not have gender and reproduce by division into two or more independent Oozemen. This process takes time and energy, however, it is completely voluntary and individuals can decide whether they want to divide or not. However, due to recent contact to other mortal races Oozemen started adopting something as gender roles and some Oozemen started to identify themselves as either male or female.
Oozemen who identify as male are usually Ruby or Gold in color and act in typical masculine way: they are loyal, brave, do not hesitate to take action, territorial and gave in-group preference. Also, they divide most often, thus there are more Ruby and Gold Oozemen than any other color Oozemen.
Oozemen who identify as female are usually Black or Emerald in color and act in typical feminine way: curious, adventurous, prioritize self-preservation, nurturing, friendly to other races and have out-group preference.These Oozemen divide more rarely and thus there are few of them.

Society.
Oozemen society is quite unique. It works similar to a democracy as the leader of society is elected by every member of Oozemen society. Every individual have 1 vote and whenever elections are held all Oozemen are required to vote. However, each elected leader leads until their death. Every aspect of their society requires 1 leader. So, Oozemen have 1 leader for economy, 1 leader for hunting, 1 leader for building, 1 leaders for social affairs, 1 leader martial arts and so on. Every time a new matter is introduced into their society their cast their votes and elect a leader to deal with that matter.
All leaders of different things in Oozemen society form the Circle. The Circle is a form of government of Oozemen society and they elect 1 other Oozemen individual to become supreme leader. This Oozeme individual can not be a leader of anything prior to being elected. Supreme leader have absolute authority over other leaders and technically have do whatever they want. To this day Oozemen had only two supreme leaders and current supreme leader (Black color) is in fact the oldest Oozemen individual alive.
In addition to absolute authority, Oozemen supreme leader get a special status and special treatment. Every Oozemen individual who dies within their society is fed to supreme leader and they will inherit minds, memories and qualities of those who they devour, so supreme leaders technically possess hundreds of minds, thousands of years worth of memories and all unique qualities of past Oozemen who died, not even mentioning that current supreme leader consumed previous supreme leader.
Supreme leader is more than just an authority in Oozemen society, but instead acts as living record of every Oozemen individual who died and is the inheritor of their will, thus other Oozemen willingly submit to their supreme leader without any question. Even banished and rogue Oozemen will do whatever supreme leader commands them to do.

Supreme Leader.
Current supreme leader of Oozemen society is the oldest Oozemen individual alive. Their name is 00012. They are abyssal slime, however, they possess all qualities of all other Oozemen types. This supreme leader, while old, is in supreme health and physical form. There is no other Oozemen individual who could best supreme leader in physical combat. Also, it is very rare to find a Oozemen wizard, cleric, sorcerer or warlock, however, as they die their powers and knowledge is inherited by supreme leader, thus supreme leaders is also an advanced wizard and can effortlessly perform 9th level spells of any school. So, supreme leader is the strongest individual in Oozemen society.
In addition, supreme leader also inherited all sorts of very rare genetic abnormalities from every other Oozemen individual who have ever died. Some of these abnormalities are like:
1) Hardening - ability to harden any part of the body and form sharp spikes;
2) Mimicry - ability to perfectly replicate physical appearance of any other creature or structure whose size is anywhere between tiny and huge;
3) Gumgum - ability to stick to any surface and move at maximum speed while moving on vertical structure or ceiling;
4) Original Clones - ability to split into two (or more) even half and later merge back together. If one half dies, then other half will take the role of the whole creature. Each "clone" have a proportional part of the stats, except for intelligence and wisdom. Every clone get full intelligence and wisdom of the whole creature;
5) Parasite Slime Paradise - ability to inject a part of your own body into any non-slime living creature and take it over. The victim will become a complete mindless slave and their mind will be completely wiped out. This ability does not work on creature of greater power than the user of the ability;
6) Living Metal - ability to replicate any non-magic weapon or armor with your own body. Also, user of this ability can clad any other creature with its own body as armor and share their own abilities with that creature through symbiotic connection.
Etc.

Way to OP for standard play. I saw a 9th lvl monk ability/spider climb,enlarge/reduce at will, Heat Vision(blind sense?), Free grappler feat ,underwater breathing and all attacks have reach... OMG im sure there's more problems than just these. And allllllllll this at lvl 1, before class factors

You've got like 3 spell effects permanently on while others can only have 1 at a time, free feat maybe, but drop the stats down to like a +1 con and dex or subraces and choose the 2nd stat. There's just too much going on here. Look at some other races get a good understanding. Maybe you can keep 3 of those 16 abilities and that's a bit of a stretch

Fair enough.