It is wrong to refer to the whole coat of arms as a crest. Technically the crest, made of light wood or leather, was worn on top of a helmet and is usually shown in illustrations above the shield on the wreath of thread which attached it to the helmet.

The coat of arms including the crest is personal and may not be used by anyone other than the current holder.

But the Clan Chiefs crest, engraved on a metal plate was said to have been worn by family and retainers, and this has given rise to the badge used by clansmen and women showing the crest within a strap and buckle with the motto round the strap. This can be worn as a cap badge or brooch but should not be used on stationary etc., without some addition such as that of the Clan Munro (Association) at the top of this paper.

The reason for the choice of crest is usually unknown; the eagle is common in heraldry but the Munro Chiefs are unusual in having eagles for charge on the shield, crest and supporters. This may derive from a play on the name of their lands 'Foulis' and "fowls of the air".

Plant badges are also associated with clans, and may be worn in the bonnet or lapel; the origin of these is also obscure but they may have been used as a form of identification. The Munro plant badge is Common Club Moss.