Legend of Goomy quest, and Deino location.

[Magus543 121]

So what are the quests needed to start the Legend of Goomy and Where can i find Deino? 

[ArcaneArceus 25]

Deino is on the Island of Angels (Angie island north of Kristaline) after showing an NPC in the Grand Dream Department a Gible.

Legend of Goomy only requires making it to Goomidra through a dive spot in Honec Woods.

[MhicKy 97]

For Deino:
As ArcanceArceus said, at one of the floors of the GDC Department Store there will be a girl with black hair wanting to see a Gible, show her and she will give you a Key Item to be used on the Altar in the Island of Angels in Kritsaline Town

For Goomy and Pawniard:
There are two requirement, the first one is finishing the quest related to the Miltank Farm, the second is finishing all the Help Center quests from Neo Gaeren, yes, even the Goldenleaf Park Restoration.. I suggest leaving that for last.. 

(Also I am not entirely sure but I THINK you also need to defeat Aya at the gym in Neo Gaeren to trigger that? But, like I said, I am not sure)

[Tikkit 31]

You do need to fight Aya. It makes sense in the quest. And the Miltank farm quest needs you to finish both of the Dr. Jenkel quests on Terajuma. Again, it makes sense in the quest.

[Magus543 121]

So the Neo Gearen quests ehh? Okay. I wanna see Goomy renact Legend of Zelda.

[kithas 118]

26 minutes ago, Magus543 said:

So the Neo Gearen quests ehh? Okay. I wanna see Goomy renact Legend of Zelda.

Hmm, that's not the only tale you will see reenacted... 

[Tikkit 31]

Yeah, I remember that time that Link fought against Moby Dick.