  We present the Kepler light curve of KIC 4552982, the first ZZ Ceti
(hydrogen-atmosphere pulsating white dwarf star) discovered in the Kepler field
of view. Our data span more than 1.5 years with a 86% duty cycle, making it the
longest pseudo-continuous light curve ever recorded for a ZZ Ceti. This
extensive data set provides the most complete coverage to-date of amplitude and
frequency variations in a cool ZZ Ceti. We detect 20 independent frequencies of
variability in the data that we compare with asteroseismic models to
demonstrate that this star has a mass M$_*$ > 0.6 M$_{\rm Sun}$. We identify a
rotationally split pulsation mode and derive a probable rotation period for
this star of 17.47 $\pm$ 0.04 hr. In addition to pulsation signatures, the
Kepler light curve exhibits sporadic, energetic outbursts that increase the
star's relative flux by 2-17%, last 4-25 hours, and recur on an average
timescale of 2.7 days. These are the first detections of a new dynamic white
dwarf phenomenon that we believe may be related to the pulsations of this
relatively cool (T$_{\rm eff}$ = 10,860 $\pm$ 120 K) ZZ Ceti star near the red
edge of the instability strip.
