  Naturalness demands that the quadratic divergence of the one-loop top
contribution to the Higgs mass be cancelled at a scale below 1 TeV. This can be
achieved by introducing a fermionic (spin-1/2) top partner, as in, for example,
Little Higgs models. In this paper, we study the phenomenology of a simple
model realizing this mechanism. We present the current bounds on the model from
precision electroweak fits, flavor physics, and direct searches at the LHC. The
lower bound on the top partner mass from precision electroweak data is
approximately 500 GeV, while the LHC bound with 5/fb of data at sqrt(s)=7 TeV
is about 450 GeV. Given these bounds, the model can incorporate a 125 GeV Higgs
with minimal fine-tuning of about 20%. We conclude that natural electroweak
symmetry breaking with a fermionic top partner remains a viable possibility. We
also compute the Higgs decay rates into gauge bosons, and find that
significant, potentially observable deviations from the Standard Model
predictions may occur.
