The interlacing of human form and Celtic knots evolved from laws forbidding drawing portraits of human figures as this was tantamount to copying a work of the creator, “God the Almighty,” explains Bain in his book Celtic Art. Similarly, it was forbidden to draw animals or plants. Angels and mythic creatures, on the other hand, were not of the earthly realm. And Saints had departed this realm. Thus, Celtic knot patterns were used to represent most of the human form, while heads, appendages and tails were often depicted using more life-like representations.]]>
Know here as the Key Pattern, or a meander or meandros (Greek: Μαίανδρος) it is a decorative border constructed from a continuous line, shaped into a repeated motif. Such a design is also called the Greek fret or Greek key design, although these are modern designations. On the one hand, the name "meander" recalls the twisting and turning path of the Maeander River in Asia Minor, and on the other hand, as Karl Kerenyi pointed out, "the meander is the figure of a labyrinth in linear form". Among some Italians, these patterns are known as Greek Lines.

'J. Romeilly Allen was of the opinion that the essential difference between the classical Key patterns and those used by the Christian Celts of Britain and Ireland, consisted in the introduction of diagonal lines by the latter.' - George Bain, Celtic Art, The Methods of Construction.]]>
The Pictish Beast (sometimes Pictish Dragon or Pictish Elephant) is an artistic representation of an animal depicted on Pictish symbol stones. It is not easily identifiable with any real animal, but resembles a seahorse, especially when depicted upright. Suggestions have included a dolphin, a kelpie and even the Loch Ness Monster.

Recent thinking is that it may be related to the design of dragonesque brooches, S-shaped pieces of jewelry from the mid-1st to 2nd century CE that depict double-headed animals with swirled snouts and distinctive ears. These have been found in southern Scotland and northern England. The strongest evidence for this is the presence on the Mortlach 2 stone of a symbol very similar to such a brooch, next to and in the same alignment as a Pictish Beast.

The Pictish Beast accounts for about forty per cent of all Pictish animal depictions, and so was likely of great importance. It is thought that it was either an important figure in Pictish mythology, and/or a political symbol.]]>