Some TMNT stuff really isn't for little kids.
- Candace Fine (debut)
- Foot Soldiers
- Merciless Slaughter (debut)
- Mondo Gecko (debut)
- April O'Neil
The turtles return to New York City, discovering a teenage rock band named Merciless Slaughter practicing in the Shredder's former hideout. Exposed to mutagen, a guy named Mondo is mutated into a humanoid gecko, Mondo Gecko, who takes down the Shredder's Foot robot.
- When the Turtles first hear Merciless Slaughter performing, the comic pages feature a real music staff with lyrics to attempt to immerse the reader into the music the characters are hearing. Stephen Murphy previously used this same kind of musical dialogue device in The Puma Blues.
- Upon returning to New York City, Raphael modifies his outfit yet again. His black bottoms, which Splinter in the previous issue #17: Fight the Power had teasingly referred to as "Jams," did not resemble actual Jams in shape then, but they do now, having been trimmed at the knee leaving Raph's lower legs and feet bare. Additionally, Raph puts on a grey dress shirt, replacing the black top he had permanently removed before going to sea in issue #16: Dreadging the Ocean Blue.
- Mondo Gecko is the last of the seven future Mighty Mutanimals to be introduced.