Martlet

From Freepedia

Note that the British version of the F4F Wildcat was initially called the Martlet.

A martlet is a type of heraldic bird similar to the swallow, but having no feet. (Swifts have such small legs that they were believed to have none at all.) In addition to being a constantly-occurring charge, it is the cadency mark of the fourth son. McGill University's arms include three martlets. The crest of the county of Sussex, England is made up of six martlets, said to represent the six traditional rape (district)s (administrative sub-divisions) of the county.