A type of the larger slaughterfish mentioned in dialogue. Put in the inner sea and padomaic ocean:

Three creatures are commonly encountered in Vvardenfell's coastal and water environments. The mudcrab, and its larger cousins the king mudcrab and mudcrab titan, are large but unaggressive. Slaughterfish are small but very aggressive, and the larger varieties, the blind slaughterfish and the electric slaughterfish, are quite dangerous. But the most dangerous water creature is the large and powerful dreugh and the dreugh man o'war.

Waiting on animations to be finished and antlers added to the herne (and the spikes removed)

Steam Colossus, a Dwemer Metal Gear
uses the Imperfect animations; would be cool for the main hall in Leftunch
emits a "shock wave" each step that it takes - the shock wave mesh is originally by Kurp
 

Redoran symbol on the shield and vivecs shield both suggest that horse shoe crab like creatures exist. 
Might be this is the creature Vivec created his shield from on a near by shore before facing the ruddy man at modern day koal cave.

The shield is referred to as a bug shield. So they could perhaps be a sort of crab like insectoid. 

The Mascots of House Redoran, giant scarabs native to Velothis.

Main references for shape are the Redorans own banners, but also included references from the Dwemer mechs (some sources say Velothis was where the dwarfs originally came from so those mechs might have been based on these creatures). This is not a claim for the mech scarabs. (https://www.tamriel-rebuilt.org/asset/proper-dwemer-scarab < thats this one) Just to make that point clear.