WARNING: Mature Content

I obviously love Eureeka’s Castle. Let’s be plain about that. I really do—it was a formative thing of my youth, I still remember the theme song, and I think it is a wonderful children’s television program. If you have children, or if you are yourself a child, consider queuing up an episode or two instead of reading what’s below. If you are like me however (a jaded adult with a treasure chest of complexes) then by all means continue onward.

Sitting at the front of the courtyard and with three pairs of eyes to see, the Fishtones bore witness to more tragedy in Eureeka’s Castle than anyone else. By the time their power grew to the point they could move themselves (albeit only a little) they had already gone quite mad, their true goals and motives changing and shifting at a whim. They have made themselves into the court and virtuoso minstrel, casting down madcap judgments and sentencing the (sometimes unjustly) accused with a song. Whether or not they can be trusted to stand against the depravity of Eureeka cannot be known, and even if it is secured they’re still likely to be as fickle as the wind.

Design Notes: This was an interesting monster to approach—obviously they’re essentially stuck in one place with no movement to be had, and on top of that it’s three monsters in one. Obviously bards, what with all the singing. So I took the gargoyle’s basics and applied them here, threw in a twist on Bardic Inspiration (so they can be more effective with spellcasting against particularly troublesome targets), and then kicked it all up a notch with Three-Headed. With a Waterjet attack they can probably knock the quickest pursuers down to slow the approach, throw out a few spells, and then get their one or two actual movements on the map (thanks dimension door) to stretch the fight out a touch. With that let’s take a look at the numbers! The DMG comes in at 8.25 and the Blog of Holding at 8.5: that’s an 8, folks!

Fishtones

Medium elemental, chaotic neutral
Armor Class 16 (natural armor)
Hit Points 75 (10d8+30)
Speed 0 ft.

Saving Throws Dex +5, Con +6, Wis +5
Skills Insight +5, Perception +5, Performance +11
Damage Resistances bludgeoning, piercing, and slashing from nonmagical weapons that aren’t adamantine
Damage Immunities poison
Condition Immunities exhaustion, petrified, poisoned
Senses darkvision 120 ft., passive Perception 20
Languages Common
Challenge 8 (3,900 XP)

False Appearance. While the Fishtones remain motionless, they are indistinguishable from an inanimate carving of three fish.

Magic Resistance. The Fishtones have advantage on saving throws made against spells and other magical effects.

Musical Inspiration (5d8/Short Rest). As a bonus action on their turn, the Fishtones can choose one other creature within 60 feet who can hear them sing. That creature gains one Musical Inspiration die, a d8. Once within the next 10 minutes, the creature can roll the die and add the number rolled to one ability check, attack roll, or saving throw it makes. The creature can wait until after it rolls the d20 before deciding to use the Musical Inspiration die, but must decide before the GM says whether the roll succeeds or fails. Alternatively, the Fishtones can grant themselves the Musical Inspiration die, and use their reaction to apply it to a saving throw being made by a creature they can see within 60 feet.

Spellcasting. The Fishtones are an 8th level spellcaster that uses Charisma as their spellcasting ability (spell save DC 16; +8 to hit with spell attacks). They have the following spells prepared from the bard’s spell list:

• Cantrips: mage hand, message, vicious mockery
• 1st-level (4 slots): healing word, hideous laughter, thunderwave
• 2nd-level (3 slots): blindness/deafness, detect thoughts, shatter, suggestion
• 3rd-level (3 slots): clairvoyance, dispel magic
• 4th-level (2 slots): confusion, dimension door

Three Heads. The Fishtones are three separate creatures forever fused into one. They gain the following benefits:

• The Fishtones have advantage on Wisdom (Perception) checks and on saving throws against being blinded, charmed, deafened, frightened, stunned, and knocked unconscious. 
• When the Fishtones cast a spell that requires concentration, they choose one head that is not already concentrating on a spell to do so. 
• Whenever the Fishtones take damage from any attack or spell, only one head (their choice) makes a Constitution saving throw to maintain concentration on a spell.
• On their turn, the Fishtones can use their action to cast three spells that have a casting time of 1 action or less.
• The Fishtones can take up to 3 reactions each round.

ACTIONS
Multiattack. The Fishtones attack three times, or it casts one spell and attacks twice, or it casts two spells and attacks once.
Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 3 (1d6) bludgeoning damage.
Waterjet. Ranged Weapon Attack: +5 to hit, range 40/80 ft., one target. Hit: 6 (1d8+2) bludgeoning damage and the target makes a DC 14 Strength check or it is knocked prone. Instead of dealing damage, the Fishtones can instead push the target 40 feet away.