Zak Morgan When Bullfrogs Croak CD....pre-owned in very good shape overall............Cross Dr. Seuss with Shel Silverstein, toss in a smidgen of a grade school educator, a G-rated stand-up comic and a folk musician, and you’ll arrive at Zak Morgan, children’s artist. The nationally sought after entertainer performs hundreds of concerts each year at auditoriums, festivals, and theatres.