Lekgolo

Ability Score Increase. Your Str score increases by 1 and your Con score increases by 2
Age. They don't mature and don't age due to being made of a lot of very tiny worm-like creatures so can live up to forever if not killed
Alignment. They tend to lean towards chaotic
Size. medium, if below half hp small
Speed. 30ft when medium 25ft when small walking speed
Language. common and convenient whispers
Immutable Form. You are immune to any spell or effect that would alter your form.
Colony.
Depending on your hp changes what you can do, when you are above half hp:
Your size is medium
Your speed is 30ft walking speed
Gain advantage on athletics checks

When you are below half hp:
Your size is small
Your speed is 25ft walking speed
Gain advantage on acrobatics checks
Can disengage or dash as a bonus action
Naturally Tough. Your hit die can't be less than a d8