Rafflesia is the final boss from Raiden Fighters.
Details
Rafflesia appears as a large rotating dome structure with multiple guns on its circumference. The boss is also surrounded by multiple large turrets and two small guns. Once it takes enough damage it activates a rotating opening around itself which reveals multiple guns below it. All of the boss's guns constantly fire barrages of bullets while the large turrets give support fire, though these can be destroyed.