  Quasiparticle excitations beyond Dirac-Weyl-Majorana classification can
appear in lattice systems due to the less symmetry constraint compared with
Poincar\'e symmetry in high energy physics. In particular, fermions with an
integer spin can appear in a variety of lattices. Here, we show that
two-dimensional spin-1 fermion may coexist with Dirac fermions in the
triangular kagome lattice (TKL). We derive a four-band effective model that
hosts both types of fermions. The effective model can be used to study the
interplay between spin-1 and spin-1/2 fermions. As an example, using this model
we show that spin-nonconserving Klein tunneling can occur in the TKL, which has
the transmission coefficient $T=1$ for normal incidence. Our findings pave a
way to the study of the interaction and interplay between different types of
fermions in lattice systems.
