Litorilinea aerophila, a filamentous member of the phylum Chloroflexota (class Caldilineae), exhibits unique morphological and cell envelope features that challenge traditional bacterial models. Although historically described as Gram-negative, Chloroflexota are increasingly considered as monoderm, lacking a true outer membrane. In this study, we investigated the growth behaviour, cell morphology, and cell appendages of Litorilinea aerophila using a combination of microscopy, electron tomography, and structural biology. Dry weight-based growth assays revealed a prolonged lag phase (~40 h) followed by exponential and stationary phases. Light and fluorescence microscopy revealed irregular constrictions along cell filaments, accompanied by a diffuse distribution of DNA, indicating a multicellular organization. Thin-section electron microscopy confirmed septa formation, and in late growth stages, filaments became shorter with more defined constrictions and membrane vesicle release. Next to the already characterised bacterial archaellum of Litorilinea aerophila, two additional types of surface appendages were identified: (i) pilus-like structures consistent with Tad pili, supported by comparative genomics, and (ii) grappling hook-like structures. These hook-like structures were related to a DUF11 domain-containing protein that was verified by quantitative mass spectrometry. These findings contribute to the understanding of cell envelope diversity, filamentous growth, and surface structures in Chloroflexota, revealing evolutionary plasticity within this enigmatic bacterial phylum.