Coral Commando

"Few Ravnicans are aware of the vast reefs in their world’s hidden ocean. Far beneath the great sinkholes, where the light is blue and dim, merfolk tend the coral labyrinths that feed the benthic ecosystem." -unknown

The merfolk of the oceans of ravnica are rather secluded deep below the surface. only some of them seek contact with the simic from time to time whilst the rest of their civilization is guarded by these warriors deep below the see.

Refferences:

https://scryfall.com/card/rna/36/coral-commando