I review anomalous single and multi-fluxon properties of Stacked Josephson junctions (SJJ's). Throughout the paper I compare analytical, numerical and experimental results both for intrinsic HTSC and artificial low-$T_c$ SJJ's. Table of Contents: 1. Introduction. 2. General Relations. 3. A Single Fluxon: 3.1. Approximate fluxon solution, 3.2. Decoupling of phase and field, 3.3. N-dependence and assymptotics, 3.4. Flux-flow characteristics, 3.5. Cherenkov radiation. 4. Multi-Fluxon Configurations: 4.1. Quasi-equilibrium fluxon modes and submodes, 4.2. Multiple-valued critical current, 4.3. Magnetic field dependence of the critical current, 4.4. Multiple flux-flow sub-branches. 5. Conclusions.