  We investigate the Schr\"odinger (non-relativistic) and the Dirac
(``relativistic") billiards in the universal regime. The study is based on a
non-ideal quantum resonant scattering numerical simulation. We show universal
results that reveal anomalous behavior on the conductance, on the shot-noise
power and on the respective eigenvalues distributions. In particular, we
demonstrate the Klein's paradox in the graphene and tunable
suppression/amplification transitions on the typical observables of the quantum
dots.
