they were extremely complicated dragons , with long beards , ears and wings , and they seemed to be frozen in motion , caught in transition from one state to another , suggesting that the loom which wove them had rather more dimensions than the usual three , but the worst thing about it was that if you looked at it long enough the pattern became blue dragons on a gold background , and a terrible feeling stole over you that if you kept on trying to see both types of dragon at once your brains would trickle out of your ears .