Were-Worms increase their Constitution by 2 and their Wisdom by 1 due to their time spent underground they need to be tough and aware of their surroundings. 

As an action, you may turn into your wormy form. All weapons, equipment, and armor you are carrying is enveloped into your form. Your form lasts for 10 minutes, and you can turn into your worm form once a day. This number increases when you reach 3rd (2 times), 7th (3 times), 15th (4 times) and 18th (5 times). When you transform, the following happens: 

• Your Armor class is 13 + Dexterity Modifier
• Resistance to Acid & Poison damage 
• Gain a Burrowing speed equal to your walking speed 
• Can make attacks with your tail using your Dexterity modifier, dealing 1d6 + DEX bludgeoning damage. 
• You cannot Wildshape or use spells that alter your appearance while in this form