Unique Origins

(+) Has poisonous fangs, which can inflict deadly poison!
(+) Can fill empty glass bottles with it's poison.
(+) Sudden Strike! -- It can jump forward with great velocity and, if timed correctly, do lethal damage!

(+) Leaves no remains, meaning that when it kills an animal mob it will gain additional saturation, when available, of course.

(+) Has keen eyesight, so it can see a little better in the dark.
(+) Can easily spot entities when camouflaging!
(+) Can shed it's skin to remove some negative status effects and add good ones instead for quite some time!
(+) While sneaking it can:
1.  Camouflage in tall plants.
2. Go faster than normal.
3. Jump higher than normal.

(=) Has green skin color.

(-) Has a thin body, meaning that it has a little less maximum life.

(-) Takes much more fall damage.

(-) Didn't evolve a way of digesting vegetables. Never needed to anyway, because it hunts animals very efficiently.

(-) It recently evolved it's arms, so they lack force to mine with the same speed as a human. However, if certain conditions are met, it can mine equally fast as other players.

(-) So with the legs, recently evolved, they lack the force to jump and move the same as a human.

(+) Makes use of the Sun's rays. Meaning it gains several positive status effects when it's under the Sun!

(+) Also makes use of the sky... somehow! Meaning that bad status effects will quickly dissipate when under the sky.

(+) Goes invisible when it wants. Mostly when someone sees it!

(+) Can also teleport whenever it wants!. Also mostly because it doesn't want to be seen...

(+) Perfect vision under water! All it took is asking the water nicely if they could see through it... And knowing the secret language, also.

(-)  It needs air! They get claustrophobic when in a cave, for example. 

(-) They fear all that is cursed, and take more damage from it!

(-) No way they are going to use shields. They hate war, and shields remind them of it.

(-) They take care of the life in the forests, like the nature and animals. They would never destroy it.

(+) After millions of years, these creatures have evolved a way of trading saturation for O2.

(+) Has thick scales (natural armor)! Which heavily protects them from a lot of damage.

(+) Does more damage while submerged in water. 

(+) Natural water vision, which allows them to clearly see through water.

(+) Natural respiration inside water.

(+) Fins which allow them to quickly swim!

(+) Breaks blocks inside water equally fast as outside.

(=) Same skin color as Guardians.

(-) Counts as an aquatic entity.

(-) Exhausts more quickly.

(-) Penalty for low saturation!

(-) Walks a bit slower on land.

(-) Starts drowning immediately if it's on land, and the penalty for low saturation is activated.

(+) Can make a big pounce to the direction it's looking at, as an ability.

(+) Incredibly good night vision for seeing where the victim is hiding!

(+) Can move incredibly fast to catch prey, or to escape.

(+) After killing so much. It mastered the ability to strike weak spots, thus dealing much more damage!
(+) It may gain wrath by using it's secondary ability and gain additional hearts and regeneration for some time!

(+) Has strong legs, to make bigger jumps when it's running.

(+) Softens falls flawlessly, making it immune to fall damage.

(+) Has long arms, so it can reach the prey safely.

(+) Can bite the enemy when doing enough damage!

(=) Has a dark skin color.

(-) Is obviously a carnivore.

(-) Has a very... peculiar skin formation. So wearing armor is uncomfortable and inefficient.

(-) It cant stand heavy armors!

(-) Gets negative effects when under the Sun.

(-) Has a lot less hearts compared to a human.

(+) Performs better on hot biomes.

(+) Has wings to fly with.

(+) Can breathe out fire!

(+) Gets motivated when fighting foes.
(+) Is obsessed with everything made out of gold, and has a lot of benefits using it!

(+) Is immune to all types of fire damage.

(+) Can launch itself into the air!

(=) Natural spawn is The Nether.

(-) Is a carnivore. So it does not digest any type of vegetables, or fruits.

(-) Arrows penetrate it's body very easily.

(-) Exhausts quicker on biomes that aren't hot enough.

(-) Can only sleep when it's sufficiently hot.

(+) When others are claustrophobic, this one actually gains positive status effects!
(+) Can mine faster and harvest ores with one less harvest level! Meaning that a wooden pickaxe can actually harvest an iron ore, for example.
(+) Can climb blocks!
(+) Is immune to lava and can walk on it.
(+) Has night vision, naturally, because its natural habitat are caves.
(-) More fall damage.
(-) Debuff when submerged in water

(-) Sinks in water right to the bottom!

(+) Killer Instinct:  natural ability that makes them hit weak spots, dealing much more damage with any weapon

(+) Efficient Nutrition:  they digest meat very efficiently, granting them more food points and saturation!

(+) Night Vision:  perfect eyesight for seeing in the darkness

(+) Excellent Camouflage:  can camouflage in tall plants, somewhat to the Snake Origin. Even though they aren't able to hide armor when camouflaging, they can remain invisible for more time.

(+) Sneaky:  when crouching, it can walk faster and break blocks silently

(+) Ambush:  when invisible, sneaking and not moving, it can release some kind of gas into the air that affects mobs in a 15 block radius, while also being granted Strength II in a window of a few seconds!

(+) Sensing:  while holding primary ability while not invisible, it can sense mobs in a 22 block radius

(+) Active Camouflage:  while holding the secondary active, it can become invisible!

(+) Omega Scales:  has capacity for much more health and is immune to lava!

(+) Claws of Steel: it can use it's sharp claws to mine faster certain blocks and do more damage when not holding anything in the main hand

(+) Agile:  it can jump high, move fast and takes much less fall damage!

(=) Purple skin color

(-) Unnatural Regeneration: unable to regenerate naturally, it needs to either be in a really hot biome or to be completely submerged in lava in order to start regenerating

(-) Differently Shaped Arms: unable to hold a shield correctly

(-) Weaknesses: takes much more damage from arrows, magic, being hit when invisible and thrown projectiles like tridents

(-) Carnivore: can only eat meat
(-) Timed Abilities: it's abilities and powers, if not used properly and in the right time, can actually lead to a disadvantage

For singleplayer:

1. Go into the "Singleplayer" menu.

2. Select the world you want this to be installed to and press the "edit" button.

3. Click on the "Open World Folder" button.

4. Open the "datapacks" folder.

5. Put the extracted files of the "zip" file in there.

6. The installation is complete.

For a server / Multiplayer:

1. Open the "world" folder of the world that you want the datapack installed onto.

2. Open the "datapacks" folder.

3. Put the extracted files of the"zip" file in there.

4. Restart the Server, you can do this by typing the command /reload in chat. (In some cases, it is preferable to completely reload the server by closing it and reopening it!)

5. The installation is complete.

I have added custom meats from the Croptopia mod in the "custom_meats" tag file.

{
   "replace": false,
   "values": [
   "croptopia:bacon",
   "croptopia:cooked_bacon",
   "croptopia:beef_jerky",
    ...
  ]
}

So the structure is like: "modname:mod_item_id"

Have in mind that these are .json files, so they need to properly be put between quotation marks, commas, etc.