Organometallic transition metal complexes are numerous and well explored. Heterobimetallic complexes containing a transition metal (M) and a heavier main group 14 element (E = Ge, Sn, Pb) have, however, only recently started to gain traction. The utilisation of main group compounds as ligands to build metal-element interactions has been hindered due to the availability of relevant fragments. Since the early 2000s, though, the library of heavier group 14 tetrylenes, ditetrelenes and ditetrylenes, compounds featuring the group 14 element in a formal +2 oxidation state, has exploded. These compounds have shown promise on their own in many transformations akin to transition metal complexes, ranging from stoichiometric small-molecule activation to catalysis. Thus, incorporation of a transition metal and a heavier group 14 element in the same moiety can allow for cooperation and complementary reactivity not witnessed for a single metal-containing complex. This chapter focuses on the chemistry of heterobimetallic complexes, where a transition metal is directly bonded to a heavier group 14 element Ge, Sn or Pb. The aim is not to comprehensively review the whole literature, but to provide the reader a holistic overview of the field, some important examples and reactivity studies with a focus on applications for the future.