char user[]={'\0'};
char* animal_holder[12]={"Ant","Bear","Cat","D…
printf("You have to guess what %c%c%c%c stands for.\n",animal_holder[a][0],animal_holde…
printf("Enter your guess:");
printf("Your choice is %s",user);


What are the errors?

Your user array can only hold a single character. Since a string ends with '\0', that means it's always going to be empty. Further, using %s in scanf() without a field width means you're not respecting the lack of available space on the array. I'm totally unsurprised that the snippet crashes.

commented: indeed +17