Marky is suave, often not really caring about what the two other roaches are doing. He is the middle child. While he originally used to love causing mischief just like the other cockroaches, he has grown to be more laid-back in later episodes, though he still enjoys hanging out with Joey and Dee Dee and continues to cause general mayhem like he has always done. Occasionally, he gets tired of Joey's controlling antics and sides with Dee Dee when he feels Joey is being too assertive.
His hobby is dating girls - sometimes even puppets or Oggy's toy dolls - and reading books. He also has bad breath, as revealed in the episode It's a Small World and Itsy-Bitsy Oggy (how he can stand his own bad breath is debatable, as he couldn't stand the smell of gas in French Fries.)
He is grey-bodied, green-headed roach with pink eyes. His body is bit thin and he is almost twice the height of his brothers. He has long, curly antennae and wears white gloves.
- He has a different set of antenna.
- Even though in earlier seasons he would hang out and be careless like his brothers, in the later seasons he would be seen more caring as than his brothers but he still likes to hang out with them.
- He does not appear in Happy Campers, Perpetual Motion, The Pumpkin that Pretended to be a Ferrari, Safari, So Good..., Sea Risks..., Abracadabra, Lost at Sea, Deep into the Wild, The Delights of Camping, Remote Controlled and At The Stroke of Midnight.
- He looks very similar to Bud from Space Goofs.
- Marky's eyes from the pilot and season 1 (a half) are red.
- He's got 2 names in Hindi, in Nickelodeon, his name is Lambu, in Cartoon Network, his name is Taplu.