Seapony Rarity from MLP the movie from screencaps.

Recomended positive tags:
+ Character: Rarity, Seapony Rarity, my little pony, seapony
+ Hair: purple hair, long hair
+ Skin: white skin
+ Tail: mermaid, mermaid tail, white mermaid tail, purple mermaid fluke
+ Eyes: blue eyes
+ Fins: purple fins
+ Ears: pony ears

Sample positive tags:

- Rarity, Seapony Rarity, unicorn, single horn, my little pony, seapony, purple hair, long hair, white skin, mermaid, mermaid tail, white mermaid tail, purple mermaid fluke, blue eyes, purple fins, pony ears

Recomended negative tags:
- legs, thigh gap, merge, merging, merged, merging hands, merged hands, purple theme, ears, scales, bad hands, bad fingers