The following is an attempt to homebrew Uryuoms from El Goonish Shive into D&D 5E as a race. It is not official, and is probably horribly balanced. But hey, somebody had to try, might as well be this idiot! (El Goonish Shive and Uryuoms copyright to Dan Shive.)
Uryuom:
Ability Scores: +2 intelligence, +1 dexterity
Size: Small
Speed: 25 feet
Age: Uryuoms age at about the same rate as humans.
Allignment: Uryuoms have a tendency toward self-actualization and mischief that makes them more chaotic then most.
Size: Your size is Small.
The Uryuom race is a fascinating oddity, their natural magic inclining them to adaptability and integration with other races to a high degree. In their baseline state, they stand two to four feet high, having skin that ranges through the lighter shades of green, blue, and purple. They are built similarly to other humanoids, though the long tail and four-fingered hands mark their forms. Their faces are dominated by a pair of black orbular eyes, below which rests a lipless mouth and above which a long pair of antennae ending in colored sphereoids sit. Individuals can grow a variety of hair styles and colors, though utter baldness is not considered abnormal
However, Uryuoms are naturally talented with transmutation magic--specifically such magic cast on themselves. While they only have limited shapeshifting abilities naturally, they are capable of absorbing any spell that transforms them and recasting it at a later date. This proficiency has affected their culture to the point that they prefer magic to makeup, and cosmetic morphing devices are a very lucrative and commonplace commodity. That said, some regulations on such devices can be rather illogical and restrictive.
Uryuoms are technically sexless, but as they tend toward integration into other cultures they usually take up a gender with which to present as determined by local norms. Due to the complexities of their reproduction, Uryuom families will generally be communal affairs, with any number of parents raising any number of children regardless of their own romantic ties. Uryuom names are usually either derived from local cultural norms or chosen to highlight a personal feature they consider important; an Uryuom with violet skin might call themselves Lilac, while a construction worker could take the name Jackhammer. These names are technically fluid, but most Uryuoms settle on a single name during their teenage years as a sort of rite of passage.
Linguistic Absorption: Your antennae are attuned toward the language centers of others minds. As an action, you may rub your antennae on any willing individual, either learning a language they know or teaching them a language you know. You regain this ability after a long rest. You have a maximum number of known languages equal to your wisdom, intelligence, and charisma bonuses added together. Languages you know through class-specific feats and traits do not count toward this limit.
Shapeshifting: The inherent nature of a Uryuom's magic allows them to not only change shape, but absorb any spell that would transform them for later use. Uryuoms have a total of four 'Shift spell' slots and, whenever they are targeted by a spell from the Transmutation school, they may choose to add it to their personal list, or replace one of their current Shifts with it. Shift Spells cannot be higher level then half the level an Uryuom is. As an action, a Uryuom may cast one of their Shift Spells on themselves; they can do this a total of two plus their highest proficiency bonus times, and regain all charges after a long rest. A Uryuom may release a Shift Spell on themselves as a free action, and automatically releases all Shift Spells on themselves upon falling unconcious. All Uryuoms start with two of the following Shift Spells:
Size: You can grow to medium size or shrink to tiny size as an action. This also increases your speed by five if becoming medium, or decreases it by five if becoming tiny.
Limbs: You can grow an extra limb as an action, to a maximum of four extra. Each limb gives you a +1 Dexterity bonus and a -1 Charisma penalty. Extra hands can be used to manipulate more things, and extra feet grant +1 each to any athletics check.
Mould: You can change your personal appearance to a degree. This can be used to change your bodyshape, hairstyle and color, and gender presentation. You will still appear as whatever race you looked like before, but you can make yourself appear as a completely different individual.
Prehensile tail: Your tail is prehensile, giving you an extra "hand" you can use to manipulate objects. You also gain +2 on any Climb or Grapple check. These bonuses are removed if you shift into a form without a tail.
Languages: Speaks Uryuomoco and one other language of their birth region.
