Carl the Arch-Lizard of Flame

 Arcane Recovery (1/Day). When he finishes a short rest, Carl recovers all his spell slots of 5th level and lower.

Legendary Resistance (3/Day). If Carl fails a saving throw, he can choose to succeed instead.

Magic Resistance. The Carl has advantage on saving throws against spells and other magical effects.

Spellcasting. The archmage is an 20th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 22, +14 to hit with spell attacks). Carl can cast Aganazzar’s Scorcher and Shield at will, and can cast Ashardalon’s Stride and Thunder Step once per day without expending a spell-slot. The following wizard spells are prepared:

Cantrips (at will): fire bolt, shocking grasp, control flames, toll the dead, blade ward

1st level (4 slots): charm person, longstrider, magic missile

2nd level (3 slots): Aganazzar’s Scorcher, Darkness

3rd level (3 slots): counterspell, Ashardalon’s Stride*, Fireball, Thunder Step, Glyph of Warding

4th level (3 slots): elemental bane, Fire shield, Wall of Fire*

5th level (3 slots): dominate person, mislead, far step

6th level (2 slot): Investiture of Flame, Sunbeam

7th level (2 slot): Delayed Blast Fireball

8th level (1 slot): Incendiary Cloud

9th level (1 slot): Prismatic Wall

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 4 (1d6 + 1) piercing damage.

Carl can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. Carl regains spent legendary actions at the start of his turn.

Cast Spell. Carl casts a spell of 3rd level or lower.

Spell Ward (Costs 2 Actions). Carl expends a spell slot of 4th level or lower and gains 5 temporary hit points per level of the slot.