  With just a month of data, JWST is already transforming our view of the
Universe, revealing and resolving starlight in unprecedented populations of
galaxies. Although ``HST-dark" galaxies have previously been detected at long
wavelengths, these observations generally suffer from a lack of spatial
resolution which limits our ability to characterize their sizes and
morphologies. Here we report on a first view of starlight from a subset of the
HST-dark population that are bright with JWST/NIRCam (4.4$\mu$m<24.5mag) and
very faint or even invisible with HST ($<$1.6$\mu$m). In this Letter we focus
on a dramatic and unanticipated population of physically extended galaxies
($\gtrsim$0.17''). These 12 galaxies have photometric redshifts $2<z<6$, high
stellar masses $M_{\star}\gtrsim 10^{10}~M_{\odot}$, and significant
dust-attenuated star formation. Surprisingly, the galaxies have elongated
projected axis ratios at 4.4$\mu$m, suggesting that the population is
disk-dominated or prolate. Most of the galaxies appear red at all radii,
suggesting significant dust attenuation throughout. We refer to these red,
disky, HST-dark galaxies as Ultra-red Flattened Objects (UFOs). With
$r_e$(F444W)$\sim1-2$~kpc, the galaxies are similar in size to compact massive
galaxies at $z\sim2$ and the cores of massive galaxies and S0s at $z\sim0$. The
stellar masses, sizes, and morphologies of the sample suggest that some could
be progenitors of lenticular or fast-rotating galaxies in the local Universe.
The existence of this population suggests that our previous censuses of the
universe may have missed massive, dusty edge-on disks, in addition to
dust-obscured starbursts.
