Quote Originally Posted by MacMillan of Rathdown View Post
The heraldic tyger (ermine or otherwise) is a mythical beast, originally derived from illustrations found medieval bestiaries, whereas a tiger proper would be the zoologically correct critter.
According to Fox-Davies, though, the spelling 'tiger' is also correct for the heraldic beast, which looks like a lion with a horn on its nose. Generally the zoological tiger is blazoned as "a bengal tiger". I think a tiger proper would simply be one in the natural colors, so "a bengal tiger proper" would be orange with black stripes.

There are plenty of other similar examples in heraldry. A seahorse is a marine beast with the body of an equine horse. What we generally think of as a seahorse is blazoned as a hippocampus. A heraldic leopard is merely a lion passant guardant (as in "the leopards of England"). A heraldic panther is a mystical beast with flames coming from its mouth and ears and blue and red spots.

Remember that most blazon is based on what medieval heralds thought certain beasts looked like. Hence, they can frequently bear little relation to what the creature in question conjures in modern minds.