if im correct ash saw a bird pokemon with or following a rainbow
so the desc says that It will reveal itself before a pure-hearted trainer by shining its bright rainbow-colored wings.
HO-OH's feathers glow in seven colors depending on the angle at which they are struck by light. These feathers are said to bring happiness to the bearers. This POKéMON is said to live at the foot of a rainbow.
Its feathers--which glow in seven colors depending on the angle at which they are struck by light--are thought to bring joy. It is said to live at the foot of a rainbow.
Legends claim this POKéMON flies the world's skies continuously on its magnificent seven-colored wings.
from db so since this legendary was with a rainbow it probibly is ho oh
once again the tail on that thing almost gives it away
2 it could be but probibly not be articuno the reasons not is because
LeafGreen A legendary bird POKéMON that is said to appear to doomed people who are lost in icy mountains.
Yellow A legendary bird POKéMON. It freezes water that is contained in winter air and makes it snow.
HeartGold The magnificent, seemingly translucent wings of this legendary bird POKéMON are said to be made of ice.
it creates snow so it might not be articuno or the designers of the ainmne ( i think ) might have made the snow sparkle.
my moneys on ho oh with 7 coloured wings and rainbows
your welcome ':)