You are Medium or Small. You choose your size when you select this race.

You are a Monstrosity.

Your walking speed is 30 feet.

Though Thri-Kreen are more likely to use their Telepathy to communicate, many, (if not all), learn to speak Common and one other language of their choice.  

You gain a +2 bonus, and a +1 bonus respectively in two abilities of your choice.

While you aren’t wearing armor, your carapace gives you a base Armor Class of 13 + your Dexterity modifier. As an action, you can change the color of your carapace to match the color and texture of your surroundings, giving you advantage on Dexterity (Stealth) checks made to hide in those surroundings.

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 discern colors in that darkness only as shades of gray.

You have two slightly smaller secondary arms below your primary pair of arms. The secondary arms function like your primary arms, and you may use them to use an object on your person as a bonus action. But, your secondary arms come with the following exceptions:

• You can use a secondary arm to wield a weapon that has the light property, but you can’t use a secondary arm to wield other kinds of weapons.
• You can’t wield a shield with a secondary arm.

You do not require sleep and can choose to remain conscious during a long rest, though you must still refrain from any strenuous activity to gain the benefit of the rest.

You have the ability to communicate mentally with any number of willing creatures you can see within 120 feet of you. A contacted creature doesn’t need to share a language with you, but it must be able to understand at least one language. Your telepathic link to a creature is broken if you and the creature move more than 120 feet apart, if either of you is incapacitated, or if either of you mentally breaks the contact (no action required).