race features:
Creature Type. You are a humanoid. You are also considered a fey for any prerequisite or effect that requires you to be a fey.
Size. Larval opterans stand between 2 and 3 feet tall, while adult opterans are between 5 to 6 feet. Your size begins as Small. When you become an adult opteran, you grow to Medium size. See the Metamorphosis trait for details.
Speed. Your base walking speed as a larval opteran is 25 feet. Your base walking speed as an adult opteran is 30 feet.
Metamorphosis. At 1st level, you are a larval
opteran. When you reach 5th level, you can choose
to undergo a metamorphosis over the course of 24
hours. After this period elapses, you emerge as an
adult opteran: you lose the Many-Footed and String
Shot traits, and you gain the Flight and Radiant Wing
traits. You can delay this change until you reach 6th
level, at which point it happens spontaneously.
Many-Footed (Larval Form Only). Having
many legs and a low centre of gravity gives you
extraordinary balance. You have advantage on
ability checks made to maintain your balance
and on ability checks and saving throws made
to avoid the prone condition.
String Shot (Larval Form Only). As an action,
you can fire a torrent of sticky string at a creature
you can see within 15 feet of you. The target
must succeed on a Dexterity saving throw
(DC equals 8 + your Constitution modifier +
your proficiency bonus) or become restrained
for 1 minute. A creature can use its action to
make a Strength check against the aforementioned
DC, freeing itself or a restrained creature
within its reach on a success. You can use it a
number of times equal to your proficiency bonus,
and you regain all expended uses when you
finish a short or long rest.
Flight (Adult Form Only). As an adult opteran,
you have a flying speed of 20 feet. To use this
speed, you can’t be wearing medium or heavy
armour.
Radiant Wing (Adult Form Only). Those
wings would dazzle any performance. You have
advantage on all Charisma checks.