The two main devices (symbols) in the Cady blazon are the piles and cockatrice. The two main tinctures (colors) are argent and gules.
Argent is the heraldic metal Silver and is usually shown as very pure white. It is also known more poetically as pearl, moon (or luna) 1Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P53. In a sketch or drawing it is represented by plain, unmarked paper 2A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1847, P11.
Red in heraldry is given the name Gules, sometimes said to be the “martyr’s colour”3The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P36. The colour is also associated with Mars, the red planet, and the zodiacal sign Aries 4Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P53. Later heralds of a more poetical nature would sometimes refer to the colour as ruby, after the precious stone.5A Complete Guide to Heraldry, A.C. Fox-Davies, Bonanza (re-print of 1909 Edition), New York, 1978, P77.
The pile was originally quite a simple shape, being a triangle reaching from the top of the shield down to a point near the lower centre 6A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Pile. A clear example being that of CHANDOS awarded in 1337, Or a pile gules. There is some argument as to the origin, Wade suggests some similarity with the meaning of “pile” in construction (a foundation) and hence that the shape could be adopted by those who have demonstrated some ability in the building trade 7The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P48. An earlier writer, Guillim, perhaps more plausibly suggested that the shape echoes those of a pennant or triangular flag 8A Display of Heraldry, J. Guillim, Blome, London, 1679, P52 The shape is quite distinctive however and became popular, leading to many embellishments to distinguish it from its close fellows, with multiple piles meeting at various points, starting from various edges and with additional decoration, leading to potentially quite complex descriptions!
Nowadays we might conflate many mythical creatures under the heading of dragon but to the heraldic artists there was a whole menagerie of quite distinct beasts, the cockatrice or basilisk being one of them. 9A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Cockatrice Whilst both the dragon and cocaktrice are winged and scaled, the cocaktrice stands on two legs rather than four. Given the reputation of the basilisk we should not be surprised to find its meaning ascribed as representing “terror to all beholders”. 10The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P86