Riddle of the Day

Yesterday’s Riddle Answer: A window.
 
Riddle of the Day: Complete this sequence of letters: o, t, t, f, f, s, s, _, _, _.

Riddle of the Day

Yesterday’s Riddle Answer: The ump and catcher.
 
Riddle of the Day: With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?