Hidden valley models are motivated by open questions in particle physics, notably the electroweak hierarchy and dark matter problems. They generically lead to “dark shower” signatures at the LHC, for which the effort to understand the hidden sector phenomenology and expand the experimental coverage is underway. For this purpose I present a complete theory of dark pions, broadly motivated by approaches to Higgs naturalness, that allows to parametrize the dark shower signals in a coherent framework and analyze the interplay with other probes, including low-energy searches at the intensity frontier. Based on work to appear in 2109.xxxxx with Hsin-Chia Cheng and Lingfeng Li.