Lion was one of the motifs used in Ashokan pillars. Lion is a solar symbol and it also represents the Buddha, as he is referred to as Sakyasimha which also means a lion among the Sakyas.
The last veda called the Atharva Veda is a collection of magic spells and charms to ward off the evil spirits and diseases. It is considered a non-Aryan work and is the latest addition to the Vedas in later Vedic age.