The first of these images was drawn circa 1986 by Pete Lenz (89). The second image was a comic discovered years later in a newspaper that seems to be appropos.
Drawing by Pete Lenz (89)
based on characters by Eastman & Laird
Pete Lenz (89), Calvin Simmons (88), Carol Shay (88), and Jim Bourn (87)
depicted as college-aged mutant ninja turtles!
an Off the Mark comic (by Mark Parisi)
Middle-aged mutant ninja turtles!