The fate of ultralight black holes depends on whether or not evaporation stops at or around the Planck scale. If evaporation stops, the general expectation is that a population of Planck-scale relics will be left over, possibly including a significant fraction of electrically charged relics. If evaporation does not stop, a runaway “explosion” would occur, with significant and potentially detectable high-energy emission. Here, I review both possibilities, with an emphasis on current status and future detection prospects.