Green Arrow is an archer in DC Comics who invents trick arrows with various special functions, such as glue arrows, diversions (smoke), net, explosive, time bomb, grappling, fire extinguishing, flash and tear gas arrows, as well as cryonic arrows, and even a kryptonite arrow. Here only smoke arrows and a refractor arrow were shown.
The relationship shown between Clark and Oliver mirrors the one Superman and Batman share in the DC comics. Even the love story between Lois and Oliver mirrors the one Lois and Bruce Wayne have in The Animated Series before she falls in love with Clark. When Green Arrow first appears, Danny Elfman's iconic five-note theme (used in the Tim Burton movie and Batman: The Animated Series) can be heard.
During the sixth season of Smallville, there was talk of spinning off Justin Hartley's portrayal of the character Green Arrow into his own series. Hartley however refused to entertain the idea, feeling it was his duty to respect what Smallville had accomplished in five seasons, and not "steal the spotlight" because there was "talk" of a spin-off after his two appearances. According to Hartley, "talking" was as far as the spin-off idea ever got.
Green Arrow's method of stealing the rich and corrupt, helping poor people is a similar trait of Robin Hood's. Hence there was a reference to Green Arrow as the 'Prince of Thieves' which is also how Robin Hood was known in English literature.
Lana Lang shows her nascent dark tendencies when she coldly threatens Dr. Groll with ruination if he betrays Lex.