Violin Plots are an alternative to box plots. In addition to the distribution summary statistics (median quartiles, etc) visualized with a boxplot, vilin plots also display the probability density distribution. See references below for details and images:
https://en.wikipedia.org/wiki/Violin_plot
http://www.cerebralmastication.com/2009/02/box-plot-vs-violin-plot-in-r/
http://eamoncaddigan.net/dataviz/r/psych/2015/09/26/violin-plots/