Questions about Frozen Turtle Shell and Ice Tortoise

[TopA]

version：1.4.3.6
I tried to fight Ice Tortoise in the Underground Snow biome all day, and got almost all the item in the area, but I didn't get the Frozen Turtle Shell
I wonder if this is a game bug?

 

[Golden Heretic Snakeboat]

Nope, just RNG ing you over, unfortunately. You'll get it eventually, it might take 5 more kills; it might take 500.

 

[TopA]

ing you over, unfortunately. You'll get it eventually, it might take 5 more kills; it might take 500.

I'll try QAQ