That is the other seal beast, Spinel Sun or
Suppi-chan.  I like his panther with wings
form myself.  Cels of him are fairly rare
but the 2nd movie had omake w Kerochan and Suppi
so some cels are showing up.  I would like
to eventually get a Suppi cel where he is drunk
or one where Kerochan is stuffing food down 
Suppi's throat from late in the TV series -
but I don't want to pay a lot for it so I will
just bide my time.