Gobwa from That Time I Got Reincarnated as a Slime / Tensei shitara Slime Datta Ken
Keep in mind that settings may vary slightly between different versions. See below for more details.
When I tested this with different checkpoints and LoRAs, it seemed to work quite well.
Pony:
A LoRA weight of 0.8 works great, though you can adjust the strength as you prefer.
Prompts I usually used:
blue hair, pink streaks, multicolored hair, streaked hair, short hair, orange eyes, white horns, small horns, facial markings, fangs, black necktie, red skirt, black belt, black thighhighs, high collar, red jacket