Horseshoe

 is a Tier 5 Tank that upgrades from Crab and Fortress at level 60.

Design
The looks identical to the Fortress but it has Crab's small intermediate guns layered under each of its spawners.

Technical
All of the barrels work identically to the way they do when attached to their parent tanks.

As the

 * Due to the placement of Fortress' barrels, you actually have some frontal firepower from your Crab barrels.

Trivia

 * The Horseshoe is probably named after the Horseshoe crab. Interestingly, horseshoe crabs are not true crabs, but rather arachnids, which means the tank still fits within the branch in a roundabout way.