Dwarf galaxies are crucial tracers of dark matter and the physics of galaxy formation and evolution. However, fundamental puzzles remain unsolved, including the diversity of their globular cluster (GC) systems, sizes, and dark matter content and profiles. In this talk, I will first present a systematic study of ∼200 dwarfs in the Perseus cluster to address the variation in GC richness among cluster dwarfs. This constitutes the largest dwarf sample in a single galaxy cluster to date with simultaneous deep imaging, spectroscopic coverage, and GC measurements, while uniquely spanning a broad and continuous range of galaxy properties. Then, I will discuss our recent findings on low-surface-brightness dwarfs with unusual star cluster systems and/or deficient in dark matter, highlighting the novel "bullet dwarf collision" scenario as a potential unified explanation for cases simultaneously having both unusual properties. Finally, I will introduce a newly launched project using Euclid to systematically analyze thousands of dwarf galaxies and their GC systems in a range of environments from the Local Group out to z ~ 0.1. The overall results will provide significant insights into galaxy formation, while the methods will provide readiness to analyze the full Euclid survey in synergy with Rubin, Roman, and DESI.
