What is the origin of the one-horned rabbit so common in fantasy and isekai stories?


Dozens of fantasy and _isekai_ stories have the one-horn-rabbit as a staple
beginner's monster.

![Horned rabbit in the Re:Monster manga](https://i.stack.imgur.com/JRnrUm.png)

Some examples:

  1. _Re:Monster_ (day 4)
  2. _I Said Make My Abilities Average!_ (ch. 19)
  3. _Kenshi o Mezashite Nyūgaku Shitanoni Mahō Tekisei 9999 Nandesukedo!?_ (web novel ch. 22)
  4. _Nidoume no Jinsei wo Isekai de_ (ch. 23)
  5. _Saikyou no Shokugyou wa Yuusha demo Kenja demo naku Kanteishi (Kari) rashii desu yo?_ (ch. 2)

What is the origin of this monster, and why is it so common?




It's possibly a reference to **[Bunicorn](https://dragon-
quest.org/wiki/Bunicorn), an early-stage recurring enemy in _Dragon Quest_
series**.

> ![bunicorn](https://i.stack.imgur.com/qTcJRm.jpg)
>
> Bunicorns are rabbits with a single horn, parodying the fabled unicorns.
> They have gray fur, and the horn is often a yellowish brown shade. [...].
>
> As enemies typically encountered at the start of a game, Bunicorns are not
> particularly strong, though they typically outweigh the likes of Slimes
> [...].

The creature first appeared on [_Dragon Quest III_](https://dragon-
quest.org/wiki/Dragon_Quest_III:_The_Seeds_of_Salvation) in 1988 (Japanese NES
release).

Considering that _Dragon Quest_ is really popular in Japan, I think this is
the most possible reason for using it as a beginner's monster, as an
alternative to [Slime](https://dragon-quest.org/wiki/Slime).

