Some TMNT stuff was always meant for grownups.

In the Mirage TMNT story Triptyche, the HMS Terrapin Terror was a remote-controlled toy boat possessed by a preteen Donatello. As the very young Turtles were playing in the sewer tunnels near their lair, they were restricted by their sensei Splinter to remain within a safe zone. But while playing, the Terrapin Terror drifted too far onto the sewer water and out of remote control range, prompting the Turtles to wander outside the limits of their safe zone to find it. It is during this little adventure that the Turtles encountered Leatherhead for the first time, though they would not be formally introduced until the Turtles' teenage years during the story Leatherhead. A mischievous Raphael threw rocks at the swimming alligator until Leatherhead erupted into rage, forcing the Turtles to run for their lives. The Terrapin Terror's mast broke off during their rough escape.
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