Your Intelligence score increases by 2, and your Dexterity score increases by 1.

Arachne have the same lifespan and reach adulthood the same as Horo Neia do.
Arachne are automatically put into adulthood when they evolve from a Horo Neia at 4 years of age and are capable of living up to 240 years.

As most Arachne stay out of society's restrictions and are not usually driven in pursuit of a cause or an objective to do good, they are typically chaotic neutral.

Arachne can be up to 7-8 feet tall and almost as wide. Weighing up to 200-400 pounds. Your size is Large.
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Even though your size is Large, your upper, humanoid torso is still of similar scale to that of other humanoid races. You count as one size smaller for the purposes of wielding weapons.
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In addition, due to your lower body, you cannot make use of mounts.
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Finally, a Medium or Smaller creature can ride on your spider back if you allow it. In such a situation, you continue to act independently, not as a controlled mount.

Your base walking speed is 30 feet.

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.

You have two creature types: humanoid and monstrosity. You can be affected by a game effect if it works on either of your creature types.

Due to your unique lower half and large size, people immediately are more afraid of you and trust you less. Disadvantage on all Persuasion and Advantage on Intimidation that involve non-monstrosity & non-aberration creature types. Disadvantage on all Stealth checks due to large size.

You are proficient in the Perception skill.

Due to your sensitivity to daylight, you roll disadvantage on all Intelligence checks, (this extends to dawn)
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Due to your adept skill during the night you roll advantage on Dexterity Checks (this extends to dusk)

You have the ability to move up, down, and across vertical surfaces and upside down along ceilings, while being able to carry objects in your hands on your upper arms. In addition, you ignore movement restrictions caused by webbing.

While in contact with a web, the arachne knows the exact location of any other creature in contact with the same web within 120ft.

At 5th level, you gain the use of webbing. It can be used for any number of purposes including rope for climbing, ensnaring enemies, or crafting traps, just to name a few. You are encouraged to be creative with your use of webbing, but you should be aware of the limit of its length. In addition, you can use the spell Web once without components — your spellcasting ability for this is Intelligence. This trait may be used again after finishing a long rest.

• You get a number of uses of webbing equal to your proficiency bonus + your Constitution modifier. This total may be renewed after a long rest. Each use of webbing takes up to 20 feet of length. For example, if you want to make a line of 20 feet, that only takes one use, but if you need a length of 25 feet, that takes 2 uses.
• You may make an attack action to ensnare a single enemy (ranged, if the enemy is not adjacent to you). You may ensnare a medium-sized creature with only one use, a large creature takes 2 uses, and so on (multiplying by 2 again for every size greater). Conversely, you may ensnare up to 2 small-sized creatures with one use, or up to 4 tiny-sized creatures with one use (given that all creatures are adjacent to each other at the time).
• The target may use its reaction to make a Strength saving throw. On a failed save, the target is restrained until either it or another creature breaks it free. The target may attempt another Strength save on each of its subsequent turns.
• If you’re targeting a specific body part or piece of equipment with your webs, you would have disadvantage on your attack action. You may choose to make such an attack in order to trip, disarm, blind, or silence your enemy with your webs. Each attempt within 20 feet takes one use of webbing.
• The webbing is only sticky in places where you want it to be (e.g. one end only for sticking to a ceiling). Webs cannot stick to wet, oily, or extremely hot (fiery) surfaces.
• Webs are vulnerable to sharp or fiery objects. An attack from those sources would have advantage against your webs.
• Web break DC and AC = 10 + your proficiency bonus + your Constitution modifier. Your webs also have 4 HP per half-inch thickness. To increase thickness per half-inch consumes one use of webbing.

You have a chitinous exoskeleton. Your AC is 13 + your Constitution modifier, but due to your body shape you cannot wear armor. A shield’s benefits apply as normal.

Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 1 piercing damage, and the target must succeed on a DC 10 Constitution saving throw or take 2 (1d4) poison damage.

Since the evolution that has made the Horo Neia what they are now, their ability to use magic has extended to their webbing. You may move your own webbing that comes from you as a Mage Hand spell at will, except that it can be used for the purposes of attacking so long as it is not holding a weapon. Such as using it as a whip, etc. This does not include any other spider's webbing or webbing from the Web spell. When moving your own webbing you cannot move mass groups of webbing. Webbing within 5ft of diameter or a single thread of webbing can be moved.

You can speak, read, and write Undercommon and one language of your choice.