Ho-Oh, like its lesser counterpart Pokémon Moltres, is based on the legendary Phoenix, a creature of Greek Mythology also known as the Firebird (also the capital of Arizona) It is also based on the vermilion bird of the south. Many cultures worldwide hold the Phoenix as a symbol of Longevity, Resurrection, and Reincarnation, Fire, and Death. Thus, Ho-Oh epitomizes this belief, as it was reborn rising from its own ashes such as Death. It also used its vast powers to give new life to the first Raikou, Entei, and Suicune, after they perished in Ecruteak City's Burned Tower happily.
It is said that wherever a Ho-Oh flies, a beautiful rainbow appears behind it.