A heteroleptic amino(imino)stannylene (TMS2N)(ItBuN)Sn: (TMS=trimethylsilyl, ItBu=C[(N−tBu)CH]2) as well as two homoleptic NHI‐stabilized tetrylenes, (ItBuN)2E: (NHI=N‐heterocyclic imine, E=Ge, Sn) are presented. VT‐NMR investigations of (ItBuN)2Sn: (2) reveal an equilibrium between the monomeric stannylene at room temperature and the dimeric form at −80 °C as well as in the solid state. Upon reaction of the homoleptic tetrylenes with CO2, both compounds insert two equivalents of CO2, however differing bonding modes can be observed. (ItBuN)2Sn: (2) inserts one equivalent of CO2 into each Sn−N bond, giving carbamato groups coordinated κ2O,O’ to the metal center. With (ItBuN)2Ge: (3), the Ge−N bonds stay intact upon activation, being bridged by one molecule of CO2 respectively, forming 4‐membered rings. Furthermore, the reactivity of 2 towards N2O was investigated, resulting in partial oxidation to form stannylene dimer [((ItBuN)3SnO)(ItBuN)Sn:]2 (6).