Iolaah is a 4th-level spellcaster. Her spellcasting ability is Wisdom (spell save DC 12, +4 to hit with spell attacks). She has the following druid spells prepared:   Cantrips (at will): druidcraft, produce flame, shillelagh   1st level (4 slots): entangle, longstrider, speak with animals, thunderwave   2nd level (3 slots): animal messenger, barkskin

Shapechanger. Iolaah can use her action to polymorph herself into a human or a dolphin. Her statistics are the same in each form, but she loses her swim speed in human form. She can use another action to return to her merfolk form.