Introducing that WATER theme, but they’re not being very clear the second part of the name.

Edit: Changed name!





Greydle Dragon

Level 8 WATER Aqua-Type Synchro Effect Monster

ATK 3000

DEF 2000

1 Aqua-Type Tuner + 1 or more non-Tuner monsters

OCG Style:

The (1) and (2) effects of “Greydle Dragon” can each only be activated once per turn.

(1) When this card is Synchro Summoned: You can target cards your opponent controls, up to the number of WATER monsters used as Synchro Materials; destroy them.

(2) If this card is destroyed by battle or card effect and sent to the Graveyard: You can target 1 other WATER monster in your Graveyard; Special Summon it, but its effects are negated.

TCG Style:

You can only use each of these effects of “Greydle Dragon” once per turn.

• When this card is Synchro Summoned: You can target cards your opponent controls, up to the number of WATER monsters used for the Synchro Summon of this card; destroy them.

• If this card is destroyed by battle or card effect and sent to the Graveyard: You can target 1 WATER monster in your Graveyard, except this card; Special Summon that monster, but its effects are negated.



Greydle Slime

Level 5 WATER Aqua-Type Tuner Effect Monster

ATK 0

DEF 2000

OCG Style:

The (1) effect of “Greydle Slime” can only be used once per turn.

(1) If this card is in your hand or Graveyard: You can target 2 “Greydle” cards you control; destroy those cards, and if you do, Special Summon this card.

(2) When this card is Special Summoned by its (1) effect: You can target 1 “Greydle” monster in your Graveyard; Special Summon that monster in Defense Position.

TCG Style:

If this card is in your hand or Graveyard: You can target 2 “Greydle” cards you control; destroy them, and if you do [destroy at least 1], Special Summon this card. You can only use this effect of “Greydle Slime” once per turn.

When Special Summoned this way: You can target 1 “Greydle” monster in your Graveyard; Special Summon that monster in Defense Position.

The [] text indicates where the card’s text is vague enough in Japanese to not be clear enough for PSCT.



Greydle Eagle

Level 3 WATER Aqua-Type Effect Monster

ATK 1500

DEF 500

OCG:

(1) If this card in your Monster Zone is destroyed (by battle or monster effect) and sent to the Graveyard: You can target 1 face-up monster your opponent controls; equip this card to that monster your opponent controls.

(2) While this card is equipped by this card’s effect, take control of that monster. When this card leaves the field, the equipped monster is destroyed.

TCG:

If this card is destroyed (by battle or monster effect) and sent to your Graveyard while it was a Monster Card under your control: You can target 1 face-up monster your opponent controls; equip this card to that monster your opponent controls.

While this card is equipped to a monster by that effect, take control of that monster. When this card leaves the field, destroy the equipped monster.

So the first part is very likely Grey, but the second part is “???” still.

Going with Greydle = Grey + Cradle (The monsters’ name is very similar sounding to Cradle)

The source article confirms there’s more than just these three.

And they’re described as “Dangerous lifeforms that seize and capture the opponent”.

Source