The paper explores the classification of unconventional fermionic excitations in solid-state systems, extending beyond the traditional categories of Majorana, Weyl, and Dirac fermions. The authors identify several new types of crystal symmetry-protected free fermionic excitations, including three-fold, six-fold, and eight-fold degeneracies, which are stabilized by space group symmetries in materials with spin-orbit coupling and time-reversal symmetry. These excitations are characterized by their degeneracies at high-symmetry points, lines, and surfaces, leading to phenomena such as Fermi arcs in non-Weyl systems and Dirac lines. The paper provides a comprehensive classification of these fermions, discusses their topological properties, and predicts the existence of materials that realize these exotic fermions near the Fermi level. Experimental signatures of these fermions, such as Fermi arcs, anomalous magnetoresistance, and chiral anomalies, are also discussed. The authors propose candidate materials for each type of fermion and outline the experimental techniques that can be used to detect these new fermions.The paper explores the classification of unconventional fermionic excitations in solid-state systems, extending beyond the traditional categories of Majorana, Weyl, and Dirac fermions. The authors identify several new types of crystal symmetry-protected free fermionic excitations, including three-fold, six-fold, and eight-fold degeneracies, which are stabilized by space group symmetries in materials with spin-orbit coupling and time-reversal symmetry. These excitations are characterized by their degeneracies at high-symmetry points, lines, and surfaces, leading to phenomena such as Fermi arcs in non-Weyl systems and Dirac lines. The paper provides a comprehensive classification of these fermions, discusses their topological properties, and predicts the existence of materials that realize these exotic fermions near the Fermi level. Experimental signatures of these fermions, such as Fermi arcs, anomalous magnetoresistance, and chiral anomalies, are also discussed. The authors propose candidate materials for each type of fermion and outline the experimental techniques that can be used to detect these new fermions.