WASP-107 is an orange K-type dwarf (about 0.68 solar masses, 4,425 K), 64.7 light-years from Earth. WASP-107 b is a super-puff Neptune with a detected helium tail: nearly Jupiter-sized, yet only a few tens of Earth masses. WASP-107 b is a 0.10-Jupiter-mass companion, with an orbital period of 5.7 days, on an eccentric orbit (e ≈ 0.09), discovered in 2017 via transit. WASP-107 c is a 0.35-Jupiter-mass companion, with an orbital period of 2.92 years, on an eccentric orbit (e ≈ 0.27), discovered in 2020 via radial velocity. The planet was found when it crossed the face of its star, producing periodic dips in brightness that reveal its size and orbital period to space-based photometry.