Gods in pagan pantheons had their own symbols, specific to each of them. Those symbols can be the animals, birds, plants and flowers, weapons and other objects from everyday life. Symbols of gods from Greco-Roman pantheon are most well-known in the world. Aphrodite (Venus), the goddess of love, was pictured as a dove, or myrtle. Apollo was associated with a bow, lyre or laurel. A bow was the symbol for Artemis (Diana) too, as well as a deer. Athena (Minerva), as the goddess of wisdom, has an owl as her symbol.
However, Athena was also a goddess of war, so she had a shield, named Aegis, as her another symbol. Ancient Greeks had the especial god of war, Ares (Mars), but his symbol was a spear. Well-known symbols are Poseidon’s (Neptune’s) trident and a thunderbolt of Zeus (Jupiter). The latter was associated also with an eagle or oak. Along with abovementioned symbols, many others were used too, for picturing the Olympian gods and goddesses.
Germanic pagan deities were no exception and had their own symbols. For example, Thor, one of the main gods in Norse and Germanic religion, was associated with thunder, lightning, oak trees, etc. His association with thunder and oak trees led to parallels with Zeus (Jupiter), but Thor had a substantially different role in Norse religion, than Jupiter (Zeus) in his relative pantheon; for example, Thor was not a head of pantheon and senior to other gods.
Bear was a sacred animal and totem of Thor and a boar was linked both to Freya and Freyr. However, most popular symbols from Germanic and Norse mythology are swastika, sun cross (wheel cross) and valknut (valknot). Swastika gained notorious reputation in 20th century because of its use in Nazi Germany, but it is one of the oldest and widespread symbols not only in Germanic, but in the whole Indo-European mythology and was known in Indian subcontinent too. As for Indian world, Mandala is another famous pagan symbol from Hinduism and Buddhism, and is popular among modern neospiritual circles.