In Alliance Tournament the flagship is a special battleship sized hull, that is immune to the banning rule, as well as allowed to fit faction, deadspace and officer mods, whereas normal ships are only allowed to fit T2/Meta/T1 mods for most parts.
As the name says there can only be one flagship for each participating alliance and once it is destroyed that alliance can not replace that ship with another one.
Here is the list of all declared flagships, alliances that did not declare one by now are not allowed to benefit from this rule:
https://forums.eveonline.com/default.aspx?g=posts&t=366021&find=unread
Most remarkable is the Raven State Issue Razor Alliance declared as their flagship, when and whether they will field it remains to be seen, but if they lose it, there will only be three left in the game.
Besides this expensive example the current AT meta seems to be built primarily around energy neutralizing, with 17 Armageddons and 15 Bhaalgorns declared as flagship.
Other than that, eleven Rattlesnakes are declared, interestingly though both finalists from last year, HYDRA RELOADED and Pandemic Legion decided for a rattlesnake as flagship.
This years Alliance Tournament will be quite interesting, as there are many alliances such as Red vs. Blue and CODE. participating and may bring some interesting new play styles into the tournament.
