A v or u-shaped head attachment commonly found on Gundams and similar mobile suits. They may be a single piece, such as on the RX-78-2, have protrusions like on the Strike Freedom, be comprised of detached segments like Harute's v-fin, or be made of energy or flames like on the Beginning Gundam and Phantom.
Please note that this tag does not necessarily implicate Gundam or a parody of the franchise, as mecha from other series may have the same design element. Examples of this include Prowl and Strongarm from Transformers and the Huckebein series from Super Robot Wars.
Similarly, not every Gundam features a v-fin, such as the Turn A, which has a mustache, G-Self, which has horns, and Ez-8, which has an antenna.
V-fins were inspired by the crests found on kabuto helmets.