A Turkey really does need to be thawed out to cook properly in the oven or to deep fry the Turkey.
Never place a frozen Turkey into a hot Turkey Fryer because it can splash oil out and cause a flash fire.
What I do before baking a Turkey is to place the frozen Turkey into the refrigerator for 4 days before I plan to bake the turkey.
The refrigerator will allow the frozen Turkey to thaw out enough to bake while keeping the bacteria away due to the cold temperatures of the refrigerator.
Thawing out a Turkey on the counter is really not safe because bacteria can grow when the Turkey sits out at room temperature.
Baking a Turkey takes around 15 to 20 minutes for each pound of the Turkey so for a 20 lb Turkey you would bake the Turkey for 300 to 400 minutes for the Turkey to be fully cooked.