The second post today is John Diggle, who first appeared in the Arrow pilot, played by David Ramsey. He was originally presented as Oliver Queen's bodyguard and driver, but has since been brought into the secret and also acts as Arrow's muscle (and his conscience). We've also slowly learned that, being ex-military, he has ties to both ARGUS and the Blackhawks.
As perhaps the only original character in Arrow, it was only a matter of time before he made the jump to comics and he finally did so in Green Arrow #24 (October 2013).
His name is a reference to well-known Green Arrow author Andy Diggle, which is also the name of Diggle's brother.