  We study the 1:4 resonance for the conservative cubic H\'enon maps
$\mathbf{C}_\pm$ with positive and negative cubic term. These maps show up
different bifurcation structures both for fixed points with eigenvalues $\pm i$
and for 4-periodic orbits. While for $\mathbf{C}_-$ the 1:4 resonance unfolding
has the so-called Arnold degeneracy (the first Birkhoff twist coefficient
equals (in absolute value) to the first resonant term coefficient), the map
$\mathbf{C}_+$ has a different type of degeneracy because the resonant term can
vanish. In the last case, non-symmetric points are created and destroyed at
pitchfork bifurcations and, as a result of global bifurcations, the 1:4
resonant chain of islands rotates by $\pi/4$. For both maps several
bifurcations are detected and illustrated.
