Sea Gronckle

The Sea Gronckle is a species of dragon that is only mentioned in the series Dragons: Rescue Riders.

Physical Appearance
No physical appearance is given for the Sea Gronckle, but it is described as being flightless, meaning that the species at the very least lacks wings.

Swimming
Sea Gronckles are described as being aquatic in nature, suggesting that the species is a strong swimmer.

Season 1
While the Rescue Riders are attempting to identify a trio of rescued dragon eggs in the episode "Bad Egg", Summer proposes a Sea Gronckle as a possible identification, but this is quickly dismissed by Leyla.