
We show that universality near a critical end point implies a characteristic relation between third- and fourth-order baryon susceptibilities chi_3 and chi_4, resulting in a banana-shaped loop when chi_4 is plotted as a function of chi_3 along a freeze-out line. Including the individual enhancements of chi_3 and chi_4 near a critical point, these features may be a consistent set of observations supporting the interpretation of baryon fluctuations data as arising from criticality.