  Rapidly rotating red giant stars are astrophysically interesting but rare. In
this paper we present a catalog of 3217 active red giant candidates in the
APOGEE DR16 survey. We use a control sample in the well-studied Kepler fields
to demonstrate a strong relationship between rotation and anomalies in the
spectroscopic solution relative to typical giants. Stars in the full survey
with similar solutions are identified as candidates. We use vsin\textiti
measurements to confirm 50+/- 1.2% of our candidates as definite rapid
rotators, compared to 4.9+/-0.2% in the Kepler control sample. In both the
Kepler control sample and a control sample from DR16, we find that there are
3-4 times as many giants rotating with 5 < vsini < 10 km s$^{-1}$ compared to
vsini > 10 km s$^{-1}$, the traditional threshold for anomalous rotation for
red giants. The vast majority of intermediate rotators are not
spectroscopically anomalous. We use binary diagnostics from APOGEE and
\textit{Gaia} to infer a binary fraction of 73+/-2.4%. We identify a
significant bias in the reported metallicity for candidates with complete
spectroscopic solutions, with median offsets of 0.37 dex in [M/H] from a
control sample. As such, up to 10% of stars with reported [M/H]<-1 are not
truly metal poor. Finally, we use Gaia data to identify a sub-population of
main sequence photometric binaries erroneously classified as giants.
