Bufog

Amphibious. Bufog can breathe air and water.

Spellcasting. Bufogs a 18th-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 18, +16 to hit with spell attacks). Bufog has following spells prepared:
Cantrips (at will): Fire bolt, Friends, Minor Illusion, Prestidigitation
1st level (4 slots): Animal friendship (Frogs and Giant frogs), Burning hands, Charm person, Command, Jump

2nd level (3 slots): Animal messenger (Frog), Flame blade, Crown of madness

3rd level (3 slots): Fireball, Hypnotic pattern, Bestow curse

4th level (3 slots): Confusion, Dominate beast, Fire shield

5th level (3 slots): Dominate person, Hold monster, Geas

6th level (1 slot): Disintegrate

7th level (1 slot): Mirage arcane

8th level (1 slot): Animal shapes (Frogs),

9th level (1 slot): Power word kill

Multiattack. Bufog makes Six tentacle attacks.

Tentacles. Melee Weapon Attack: +16 to hit, reach 8 ft., 1 target. Hit: 40 (4d20) bludgeoning damage and target is grappled. 

Eye Ray Ranged Weapon Attack: +16 to hit, range 60/100 ft., four targets. Hit: 50 (10d10) Fire damage plus 50 (10d10) psychic damage.

After a creature takes an action, Bufog can use an Legendary action. Bufog can make three legendary actions per rest.

FIre bolt. Bufog casts the Fire bolt Cantrip.

Eye Ray (Costs 2 Actions). Bufog uses its Eye Ray action.