[tatami]

yeah its right it is only shown that kyuybis appereance is shown as fire but it is not...it is not even its true physical appereance...more of it in the first episodes kyubi was shown like an ordinary fox (sound funny ) with 9 tails and huge body

but:

Spoiler for elementals for bijuu:

there are affinity for them i think cuz kisame told something like that