Step 1: Prophecy.
At the time of the Tiger King's birth, astrologers predicted his death would come from a tiger.
Step 2: Detailed warning.
The chief astrologer warned that the King should beware of the hundredth tiger.
Step 3: Significance.
This prophecy shaped the King's life, leading him to hunt ninety-nine tigers.
Step 4: Conclusion.
Ironically, his death came not from a tiger, but from a wooden toy tiger—the hundredth tiger.
Final Answer: \[ \boxed{\text{The astrologer predicted that the Tiger King would die due to the hundredth tiger.}} \]