Your Constitution increases by 2 and another trait of your choice increases by 1.

As an ooze, your body has no one specific shape or form. This allows you to change your shape at will and you can shift between small and medium size as a free action. your shape cannot extend beyond your size constraint and you cannot increase or decrease your weight with this feature. you can mimic the appearance of other races or creatures, but you cannot change your color to mimic them.

Your creature type is both humanoid and ooze for the case of spell targeting and affects. You also don't need to breath or sleep.

Slimefolk, being creatures of gelatinous slime, are naturally sticky. You have advantage on Strength (Athletics) checks made to grapple a target. In addition, you can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Your liquid body allows you to move through areas as small as 1 inch without squeezing. When you do so, any objects too large to fit through the space are left behind and equipment you're proficient with are merged into your form as you move through the space.

Jellies are naturally corrosive, as such, your unarmed strikes deal acid damage equal to 1d4 + your Constitution modifier, instead of the bludgeoning damage normal for an unarmed strike. In addition, you are resistant to acid damage.

As a bonus action, you can extrude a pseudopod that is up to 6 inches wide and 10 feet long or reabsorb it into your body. As part of the same bonus action, you can use this pseudopod to manipulate an object, open or close a door or container, or pick up or set down a Tiny object. The pseudopod contains no sensory organs and can’t attack, activate magic items, or lift more than 10 pounds.

As a bonus action while grappling a target up to your size, you force the target to make a Strength save vs 8 + proficiency + Strength. On a failure you engulf the targets in yourself, the following occurs while engulfing a target.

• While engulfing a target, you regain use of your hands for the purposes of taking actions, may only engulf one creature at a time and you move at half your movement speed. You may release an engulfed target as a bonus action. When you take damage while engulfing a target you must make a concentration check, on failure you release the target. The target is released if it grows larger then your size while engulfed.
• The engulfed target is restrained, blinded, silenced and deafened. You may choose if the engulfed creature takes 2d6 damage Acid damage on the start of its turn and it must reroll its saving throw to escape. If an engulfed target needs to breath it begins to suffocate on the end of it's turn, as a free action you can declare if the engulfed target can breathe. When released the target is knocked prone in an unoccupied space within 5ft of you. The damage increases to 3d6 at 6th level, 4d6 at 11th level, and 5d6 at 16th level.
• When an engulfed target dies, you gain 1d4 + your proficiency in temporary hit points. The corpse dissolves and you regain your full movement.

For Jellies, water is both an essential part of life and a death sentence. You require twice as much water to avoid exhaustion than other races, standing in the rain is a substantial source of water for this purpose. Too much water, however, is dangerous for you. If you start your turn in a body of water, such as a lake, an ocean, you take 1d6 necrotic damage at the start of each of your turns. If this damage reduces you to less than half of your maximum hit points, you are considered to be poisoned until your hit points are restored to over half your hit point maximum. Finally, if you are reduced to 0 hit points by this trait you die.