I found a reliable source for these to be 上古龙蛙.
He's basically always up and always gives me 3 hides on the first kill of the day.

Drops on the first kill of the day:
(3x 致密之皮) - 上古龙蛙 / 觉醒海岸
/way #2022 77.6 22.4 Ancient Hornswog

(3x 异彩鳞皮) - 领地水滨幼崽 / 欧恩哈拉平原
/way #2023 23.0 66.6 Territorial Coastling

(3x 异彩鳞皮) - 赤鳞巨兽 / 欧恩哈拉平原
/way #2023 63.2 48.6 Sunscale Behemoth

(3x 致密之皮) - 斯卡拉 / 欧恩哈拉平原
/way #2023 45.2 48.4 Skaara

(3x 致密之皮) - 赫恩拉尔 / 索德拉苏斯
/way #2025 55.6 77.2 Henlare

~~(3x 致密之皮) - 泥沼怪 / 碧蓝林海~~ Removing as recent kills gave me no hides.

Any skinnable Rare or Rare+ mob will drop either these or hides once a day. Examples of mobs that drop Lustrous Scales are 沃尔卡纳克, 领地水滨幼崽, 赤鳞巨兽, 加兹拉克西斯.

Any skinnable Rare or Rare+ mob will drop either these or hides once a day. Examples of mobs that drop Lustrous Scales are 沃尔卡纳克, 领地水滨幼崽, 赤鳞巨兽, 加兹拉克西斯.

I just picked one up from a Primal Proto-Drake in Waking Shores.
Color me surprised.

小知识

屏幕截图

视频

异彩鳞皮

物品等级：60

制作材料
品质：

"由拥有剥皮技能的玩家收集。可以在拍卖行购买和出售。"

最大叠加: 1000

售价: 3

钓鱼地点

此物品位于觉醒海岸（4），欧恩哈拉平原（3），和拜荒者的未来（2）.