Petrifying Gaze: DC 14 Con save at start of turn if creature can see Cassiopeia's eyes, she is within 30 feet, and she is not incapacitated. Fail by 5 or more, it's petrified instantly. Otherwise, restrained, and repeat save at end of next turn or be petrified (end effect on success). Creature can avert its eyes at start of turn, effectively blinding it to Cassiopeia. If she sees her own reflection under the above conditions, she is subject to her own curse.
Snake Hair: +5 hit, 1d4+2 piercing damage plus 4d6 poison damage.
Spellcasting: Cassiopeia is a 9th-level spellcaster. Her spellcasting ability is Int (DC 14, +6 hit). She has the following wizard spells prepared:
--Cantrips (at will): Ray of Frost, Minor Illusion, Mage Hand, Prestidigitation
--1st level (4 slots): Detect Magic, Disguise Self, Magic Missile, Shield
--2nd level (3 slots): Snilloc's Snowball Swarm, Hold Person
--3rd level (3 slots): Counterspell, Fireball, Slow
--4th level (3 slots): Greater Invisibility, Ice Storm
--5th level (1 slot): Cone of Cold