This is the first of two races I've created for a homebrew setting that may be posted at some point. The setting is based on Mediterranean and Mesopotamian mythology, with an emphasis on some of the weirder yet more mundane bits. This race is inspired by a fantastical Scythian tribe of one-eyed men who stole from griffons, as described in Herodotus' Histories. I have taken some pretty clear liberties.

The one-eyed arimaspi have some connection to both the Astral and Ethereal Planes; some believe these connections to derive from a history with aberrations. Whatever their origins, the arimaspi seem as different from the mortals of Edaphos as the occasional travelers from those planes. Their central rite of passage into adulthood, which echoes throughout their society, requires that they singlehandedly steal at least one gold item from the hoard of a griffon, a test from which only three-quarters of youths return. Under arimaspi law even the most minor crime requires a large and strictly delineated burden of proof, but likewise incurs a draconian penalty; this causes both outsiders entering arimaspi lands and arimaspi subject to foreign laws to experience severe culture shock.

Ability Score Increase. Your Dexterity score increases by 2, and your Intelligence score increases by 1.
Age. Arimaspi grow slower than humans, reaching maturity around age 20, though an arimaspi is considered an adult no sooner or later than they can complete their rite of passage. They remain vital until their death, which usually occurs by age 90.
Alignment. Despite seeming chaotic, arimaspi's adherence to tradition and rigorous legal code cause most to tend toward lawfulness. Agnostic to good and evil at home, wandering arimaspi are easily swayed to share the views of whatever companions they accrue.
Size. Arimaspi are usually at least 6 tall and lanky, with long necks and limbs. Your size is Medium.
Speed. Your base walking speed is 30 feet.
Darkvision. The ethereal magic empowering your eye also grants you superior vision in dim and dark conditions. 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.
Ether Sight. As a bonus action, you can shift your vision, allowing you to see the Ethereal Plane. You cannot see in the Prime Material, and you cannot hear or interact with the Ethereal Plane. This effect lasts for 1 minute, or until you use a bonus action on your turn to end it early. Once you use this ability, you can't use it again until you finish a short or long rest.
Light Fingers. You are proficient with the Sleight of Hand skill.
Palm & Produce. You have access to two personal pocket dimensions, each connected to one of your hands. Each dimension has flexible volume and can contain objects weighing up to a total of 10 pounds. Examining one of your palms reveals the total weight of the items stored in the corresponding dimension, but not its exact contents.
Storing or withdrawing an item in one of your pocket dimensions takes as long as storing or withdrawing it on your person. Magical storage items, such as a bag of holding or portable hole, are incapable of being deposited into your pocket dimensions.
Languages. You can speak, read, and write Common and Arimaspi.

Spoiler: OPTIONAL: Loss of Hands and Fingers
If one of your hands is severed, the contents of the corresponding pocket dimension immediately emerge from the hand, and you lose access to that dimension. If one of your fingers is severed, the total weight that can be stored in that hand's corresponding pocket dimension is reduced by 2 pounds; if this renders the dimension's contents too heavy to be stored, items emerge from your palm, in order from heaviest to lightest, until the weight in the dimension is reduced below the new limit.