> For the complete documentation index, see [llms.txt](https://docs.koins.run/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.koins.run/aspects-of-a-koin/physical-atributes/body-parts/dorsal.md).
# Dorsal
The tail is a key piece of a koin, and they come in many different forms. Its upper fin, in addition, always matches its tail. We call the set of both elements the dorsal.
**Bonnet**
This type of dorsal is the most common among the koins, providing just enough technique to let them show off at races.
**Brush**
With this common set of larger fins and tail, koins with these features are ready to paint their rivals' defeat.
**Beak**
Similar in appearance to that of a mighty bird, this tail appears to start and end at the same time. Makes for a fantastic set with its upper fin.
**Bow**
A rather uncommon sight, this elegant dorsal is simple, yet makes a statement.
**Blade**
Don't swim near this rare tail, or you might wind up cutting yourself on its sharp appearance. Also, watch out for its upper fin!
**Bait**
With this rare dorsal, the lure becomes the lurer! So small, yet so powerful.
**Bellows**
This rather rare back is a spectacle anywhere it goes, leaving in its wake, a trail of admiration.
**Blackfly**
While it’s completely harmless, this particularly rare stinger of a fin makes opponents think twice before trying to pass.
**Basil**
Only a small batch of koins come with this particular back, which seems to leave a sweet scent on any track it’s displayed.
**Bight**
Commanding glances anywhere it goes, this set brings up an immediate urge to surf whenever it’s seen. Cowabunga!