This study identifies 341 faint, reddened active galactic nuclei spanning redshifts z=2-11 dubbed 'little red dots', indicating a previously hidden, dust-obscured phase of black hole growth. They rapidly emerge at z~8, possibly tied to inside-out galaxy growth, before declining by z~4.5. Though 2-3 dex more abundant than bright quasars, they are only 0.6-1 dex more comm...