I hope that's not what it is!

Do not use dry ice in individual drinks. Use only in large punch bowls for effect.
Under no circumstances should dry ice be placed in the mouth.Do not allow dry ice to come in contact with bare skin or other bodily tissue. Keep the dry ice in its packaging at all times. Dry ice has a temperature of -79°C and direct contact can cause freeze burns. If you must handle dry ice, use gloves or newspaper.
But apparently not poisonous...
No it will not poison you to drink a liquid that is directly cooled by dry ice. At normal pressures there may be some gaseous CO2 dissolved in the liquid giving it a mild carbonation. However, dry ice can be dangerous to bare skin, mouth, or GI tissue if someone swallows a medium to large pieces of dry ice. Small pieces are not poisonous, but can produce an unpleasant popping or tingling sensation in the mouth (like extra tingly PopRocks). In a process similar to making liquid nitrogen ice cream, dry ice can even be used to make ice cream if it is crushed very finely.
https://cooking.stackexchange.com/questions/25817/can-dry-ice-in-a-liquid-poison-you/25818