Coach Z is the "coach" of the residents of Free Country, USA, though it is unclear exactly which sports he coaches. He has a strong accent, based on an Upper Midwestern accent (though it is also sometimes simply nonsensical) which is sometimes difficult for other characters to understand. While occasionally tiresome, he is always ready to offer encouragement and is rarely critical of anyone. When giving advice, he tends to start with the phrase "You can't just rush into the score zone", which has lost its meaning through time.
Coach Z wears a blue and purple baseball cap and a large gold Z emblem around his waist. Nobody knows for sure whether his bright green color is his skin or a body suit. However, baby Coach Z seems to be wearing footy pajamas in the email highschool, and on more than one occasion, Coach Z has mentioned his pants. In shapeshifter, Coach Z referred to his outfit as his "sweaty sweat-sweats", which was seen to have at least one pocket. His head is a white sphere with light gray circles for eyes. Coach Z lacks a visible nose and mouth, but is able to talk, eat and spit with ease. He has long arms and large feet, but very short legs.
As Coach Z himself is not afraid to admit, he's got more than two problems. Despite being a coach, he doesn't know what a basketball is, as indicated in secret recipes. It has been strongly implied that he has a crush on Marzipan, and he has occasionally made inappropriate comments about her; one occasion on her answering machine when he was drunk, and another during the commercial break of the 4Tst annual Fall Float Parade. In diorama, Coach Z even refers to Marzipan as his "gorgeous girlfriend". He also has difficulty pronouncing certain words, such as "job" (as shown in the "A Jorb Well Done" cartoon), instead pronouncing it as "jorb", "jaerb", or "jorearb". In addition to his frequent mispronunciations, Coach Z also seems to have mental and gender confusion problems, as evidenced by the time he spent "talking to his parents" on a disconnected telephone, and claiming to be a mother in garage sale. He has even stated on one occasion that he sometimes "forgets what's real, and what's just in [his] head". He has an apparent fixation with butts, and he seems to have a habit of butt-patting. Many characters see him as a nuisance. Even Homestar treated Coach Z with contempt in Decemberween Short Shorts, quickly refusing to allow Coach Z to come to his house for Decemberween.
When not working as a coach, Coach Z works with Homestar Runner and Bubs as the apparent local law enforcement in Free Country, USA. Coach Z is also the janitor at the office where Homestar and Strong Bad work. He is paid on hourly wage and is clearly jealous that Strong Bad is paid on salary. He has also spent time dressed as the Blubb-O's Drive-Thru Whale mascot. Coach Z owns four Tony awards, suggesting that he may have a background in theatre. Despite his numerous jobs, Coach Z has trouble managing his money, causing his electricity to be shut off each year.
Coach Z is a fan of hip-hop and rap music, particularly the Wu-Tang Clan. He fancies himself a rapper as well: He released the single "These Peoples Try to Fade Me," which appeared on Strong Bad Sings and Other Type Hits, his solo album, entitled "The Z Is All Up Ins", features the smash hit "Hip Hop Dance", and his own rap song, "Rap Song" (featuring Peacey P and Tenerence Love). Although his usual rapping prowess consists mainly of "count[ing] to two over and over again," as explained in nightlife, he once had a very successful career during his days in the Two-o Duo.
Coach Z's age is ambiguous, as he appears to be grown up when Strong Bad was a kid in the email stand-up, while they both appeared to be babies in the email highschool (although this may simply be a product of Strong Bad's "doodle memory"). He is likely to be one of the older characters, since in caffiene, Strong Sad's slaps provoke him to cry out "I'm just an old man!" and in slumber party, Strong Bad refers to him, Bubs, and The King of Town as "older kids."
Coach Z and Bubs had a falling out at one point, as Fall Float Parade shows us; Bubs makes a "Coach Z, you jerk!" float for the parade, and Coach Z retaliates by saying "Serves him right, then" when Strong Mad steals his concession stand. In the email narrator, it was shown that they had made-up and returned to having boring conversations about Bubs's napkins. However, in Most In The Graveyard, when it is implied that Coach Z fancies Bubs' sister, Bubs beats him up. In the same toon, it is also revealed that Coach Z and Bubs may actually be very distant cousins, although Bubs finds this hard to believe.
On the maps and minions board in the king of town's castle in Strong Badia the Free there is a country called Coachnya which is ruled by Coach Z. Its location is unknown as it is never visited, but it is likely to be around either the race track or the gymnasium, as Coach Z says it has a scoreboard. Coachnya buys up all the weapons from Concessionstan's black market in order to defeat the Fhqwhgadi rebels.
Also Strong Bad reforms a band he used to have with Bubs to enter into the Battle royale of the bands in Baddest of the Bands.