It's available while supplies last at a suggested price of $2.79 for a regular 16-oz shake and $3.29 for a large 24-oz shake.
I imagine it's somewhat similar to the Mint Oreo Shake they sometimes offer but pink instead of green. Previously, they went for an Eggnog Shake around this time of year.
Nutritional Info - Jack in the Box Peppermint Oreo Shake - Regular (16 fl oz)
Calories - 881 (from Fat - 403)
Fat - 45g (Saturated Fat - 30g)
Sodium - 367mg
Carbs - 111g (Sugar - 89g)
Protein - 12g