You can’t use equipment made for creatures larger than you by normal means

Your Hit Die decreases by one step.

You can move through and stay in the same space as another creature. You gain half cover while in an allied creature’s space.

Any weapon damage dice you roll decrease one step. This doesn’t include bonus dice from class features, such as Sneak Attack, or special traits.

You can repurpose small objects to replicate larger weapons and items. This includes small gear meant to be used differently, such as a sewing needle for a rapier, or a chisel for an axe. If you replicate a weapon that has the heavy property, it loses that property.

You also gain proficiency with improvised weapons, and can use them as if they had the finesse property.

You have two creature types: one provided by your base creature below, and your choice of Celestial, Fey, or Fiend. An effect that affects either of your creature types affects you.

When determining your character’s ability scores, increase one of those scores by 2 and increase a different score by 1, or increase three different scores by 1. Follow this rule regardless of the method you use to determine the scores, such as rolling or point buy.

The “Quick Build” section for your character’s class offers suggestions on which scores to increase. You’re free to follow those suggestions or to ignore them. Whichever scores you decide to increase, none of the scores can be raised above 20.

No matter their shape or form before becoming a mousquetaire, the base creature doesn’t age.

Your size is Tiny.

Your walking speed is 20 feet, and you have a climbing speed equal to your walking speed.

Choose one of the following base creatures to inhabit. This body takes on a more humanoid appearance when you assume control:

Insect. You are a Beast. You have proficiency in the Athletics skill.

Object. You are a Construct. You do not need to eat, drink, or breathe. While you remain motionless, you are indistinguishable from an ordinary object.

Plant. You are a Plant. You do not need to eat. Each day at dawn, you grow a number of berries equal to your proficiency bonus. You can feed one of these berries to a creature (or it can consume the berry on its own) as a bonus action to restore 1 hit point. The berries lose their potency after 24 hours.

Rodent. You are a Beast. You have proficiency in the Perception skill.

Undead. You are an Undead. You do not need to eat, drink, or breathe. You have resistance to necrotic damage.

You don’t take damage as a result of falling.

When you take damage, you can use your reaction to immediately take on an otherworldly glow. For 1 minute, you gain the following benefits:

• Once on each of your turns, you deal an additional 1d4 force damage to a target when you deal damage to it with an attack or spell.
• When you make a saving throw, you can use your reaction to roll a d4 and add the number rolled to the saving throw.

You can’t use this trait again until you finish a long rest.

You can speak one language of your choice and a second language based on your second creature type (Celestial for Celestial, Sylvan for Fey, and Abyssal or Infernal for Fiend).