Snapdragon or Antirrhinum.  The name comes from the Greek words anti meaning “like” and rhis meaning “a nose or snout” referring to the flower which resembles a dragon’s nose or snout.  If it is gently squeezed the flower’s mouth opens then snaps shut like a dragon’s mouth.  In Spain it is called “dragon's mouth" and in several other countries it is a "lion's mouth."
Apparently the Romans believed that the flowers could ward off witchcraft and evil charms and the yellow ones represented joy and happiness so our garden should be safe from harm!