The god Apollo played a significant role in the mythology of the ancient Greeks.
Bow - As the god of archery, it stands to reason that Apollo would be represented with a bow in both myth and art. Incidentally, Apollo shares this attribute with his sister Artemis.
Deer - Both Apollo and Artemis share the deer as one of the animals that represent them in artistic depictions.
Laurel - The laurel is especially identified with Apollo. There is a compelling story about how Apollo became associated with the laurel, and it involves a nymph named Daphne.
Tripod - There is a legendary connection between Apollo and the oracle at Delphi that is revealed in this symbol.