Dry ice is one of the names given to solid carbon dioxide (CO2); It is sometimes called cardice.
When dry ice sublimes, it can cool bodies to low temperatures, and in contact with water it is used to produce mist effects on stage.
Part of the polar ice on Mars is dry ice. When it sublimes in the spring it causes landscapes to appear with strange features in the form of fans, lace and spiders.
An example of a feature on Mars caused by the sublimation of dry ice. Credit: Nasa/JPL/University of Arizona