Acidic dragons can spew deadly acids and release poisonous gases. Their bite releases a highly toxic venom that is more than likely to kill those who are inflicted. Their blood is also poisonous and another reason to take caution. They are the only type of dragon to have warning coloration. 

Toxins - Can release deadly acids and poisons through spit or bites. 

Antivenom - Can create an antivenom for any venomous bite. 

Toxic Gas - Acid elementals can release toxic gases that lessen the air quality/burn the lungs of others. 

Toxic waste - The ability to corrode any material or thing into a toxic sludge.