One could say that Keke was meant to be born in the distant past, but due to human-imposed seals, it only truly arrived in this world hundreds of years ago.
And, this little thing is naturally a heavy sleeper, sleeping for decades or even a century at a time. When seriously calculated, the time it's been awake barely totals to five or six years, hence it still acts like a child.
Since ancient times, although the Dragon Clan has been concealing the truth, the news has still leaked out. Many old timers are aware that an unparalleled little demon has appeared on Dragon Island, entwined with endless curses.
Moreover, the tale got more exaggerated in spread, Keke was the ominous little beast that defied the heavens, a sign of imminent extinction for Dragon Clan, and even other races could be affected. Naturally, some people fanned the flames, not wishing such a defiant creature to exist in the world.