- Delicious Walkers Monster Munch Roast Beef flavour snacks - Multipack contains 6 x 20g packets of Walkers Monster Munch Snacks - Each pack contains 98 calories - Crunchy, tasty and totally spooky, Monster Munch are a family favourite - Baked not fried and contain no artificial colours - Suitable for vegetarians. 98 kcal 412 kJ Per Pack. Baked Not Fried. Suitable for Vegetarians. Walkers.