Newman makes his first physical appearance in "The Suicide", but he is first established as a character in the earlier episode "The Revenge", in which only his voice (provided by Larry David) is heard.
Newman's role is primarily as Jerry's nemesis and a frequent collaborator in Kramer's elaborate and bizarre schemes.
Newman's own talents as a poet and wordsmith are considerable, yet recognition similar to Jerry’s has so far eluded him.
Earlier in the same episode, Jerry reluctantly agrees with George that Newman is "merry", which appeared to be a compliment of sorts.
He can climb trees very well ("like a ring-tailed lemur", as Kramer puts it), a skill he claims to have learned in the Pacific Northwest.
Despite taking pride in his work, Newman is paradoxically portrayed as a slacker who has bad habits like hiding bags of mail in Jerry's storage locker in the basement rather than delivering them.
He has been known to occasionally use his position for unethical ends, such as deliberately withholding mail (often utility bills or the like) for the purpose of blackmail, retaliation, or using his union to get out of jail.
Newman has unrequited romantic feelings for Elaine over the course of the series, but in "The Reverse Peephole", he rejects her advances when she tries to seduce him to get back a fur coat, out of loyalty to his current girlfriend.
Your day of reckoning is coming, when an evil wind will blow through your little playworld and wipe that smug smile off your face!
When they are arrested in "The Engagement", Newman assures Kramer and Elaine that they will not be prosecuted: "In 20 minutes, that place'll be swarming with mailmen.
George, upon learning it, asks "Aren't [postal workers] the guys that always go crazy and come back with a gun and shoot everybody?"
In "The Junk Mail", Kramer realizes the Postal Service has become obsolete and starts an anti-mail campaign; he is later abducted by Post Office security men.
"[1] Series co-creator Larry David conceived the character when writing the script for season two's "The Revenge".
He was set to appear in one scene, in which he explained that he jumped from the apartment building, but an awning had broken his fall.
[7] While conceiving a plotline for the third-season episode "The Suicide", the writing staff decided to create a friend for Kramer.
[3] David immediately thought Knight was "terrific" for the part,[3] and was also amused by his hefty appearance as opposed to Kramer's slim figure.
[9] Though Seinfeld felt introducing a friend of Kramer might ruin the character's mystique, Knight's performance convinced him otherwise.
To establish better continuity, Knight re-recorded Newman's lines in "The Revenge" for the syndicated version of the episode.
[6][11] When it was announced in 1998 that the show would end, Knight proclaimed "I'm gonna burn all of Newman's clothes and those funky black shoes I've been wearing all these years.
"[12] Prior to the finale, The New York Daily News asked Knight if he would be interested in a spin-off focusing on Newman, to which he replied, "I think he could show up on Law & Order as a snitch, but as for a weekly dose of Newman, well, I think if occasionally you're hit in the head with a ball-peen hammer, you might get slightly dazed.
"[13] In a Sacramento Bee interview, Wayne Knight explained that he was once pulled over by a police officer who merely stopped him to say "Hello, Newman" to him.