So I have some suggestions for Dryads that could be.. interesting.

Treeshaper - Dryad that will occasionally help with construction.

Stonerooter - Dryad that will occasionally Mine designated mining spots (Similar to the Moles in Alpha animals)

Nymph/Melody/Wildsinger - These dryads will occasionally sing lovely little songs to give minor mood boosts to colonists.

Lifegiver - Dryad that will occasionally give an injured pawn a minor boost to the recovery of one of their injuries. Basically increase the natural healing rate for 1 injury at a time. (Could theoretically try to patch up wounds as well on injured pawns? Maybe when they follow their drafted master they provide healing and medical attention to nearby pawns?)

Grovetender - These dryads basically harvest and sew new plants up to a certain level in designated fields. They might occasionally plant trees in free areas as well.

Beastwhisperer - These dryads help train and maintain the beasts of your colony, keeping them nice and tame and helping them learn to be more beneficial to their masters.

Ancient Dryad - This is a unique dryad that would actually consume 2 dryad slots instead of 1. This means you'd need 30%- 40% for 1 Ancient Dryad and 70-80% for 2 ancient Dryads. These dryads are fairly durable and can hold their own in a fight. The key thing about Ancient dryads though is they provide a constant, passive increase to research as they very slowly share their ancient knowledge.