  We propose a two Higgs doublet Type III seesaw model with $\mu$-$\tau$ flavor
symmetry. We add an additional SU(2) Higgs doublet and three SU(2) fermion
triplets in our model. The presence of two Higgs doublets allows for natural
explanation of small neutrino masses with triplet fermions in the 100 GeV mass
range, without fine tuning of the Yukawa couplings to extremely small values.
The triplet fermions couple to the gauge bosons and can be thus produced at the
LHC. We study in detail the effective cross-sections for the production and
subsequent decays of these heavy exotic fermions. We show for the first time
that the $\mu$-$\tau$ flavor symmetry in the low energy neutrino mass matrix
results in mixing matrices for the neutral and charged heavy fermions that are
not unity and which carry the flavor symmetry pattern. This flavor structure
can be observed in the decays of the heavy fermions at LHC. The large Yukawa
couplings in our model result in the decay of the heavy fermions into lighter
leptons and Higgs with a decay rate which is about $10^{11}$ times larger than
what is expected for the one Higgs Type III seesaw model with 100 GeV triplet
fermions. The smallness of neutrino masses constrains the neutral Higgs mixing
angle $\sin\alpha$ in our model in such a way that the heavy fermions decay
into the lighter neutral CP even Higgs $h^0$, CP odd Higgs $A^0$ and the
charged Higgs $H^\pm$, but almost never to the heavier neutral CP even Higgs
$H^0$. The small value for $\sin\alpha$ also results in a very long lifetime
for $h^0$. This displaced decay vertex should be visible at LHC. We provide an
exhaustive list of collider signature channels for our model and identify those
that have very large effective cross-sections at LHC and almost no standard
model background.
