Taxonomic chimeras, artificial taxa created unintentionally by amalgamation of morphological traits belonging to different taxonomic units, can be found in 19th century to present day scientific literature. We recognise two types of such artefacts in Ostracoda. Chimera Type 1 is represented by species defined by morphological traits belonging to two (or more) different valid taxa at the rank of species. A thorough comparative analysis of carapace and limb characteristics of Fabaeformiscandona balatonica (Daday) sensu Bronshtein (1947) allows us to conclude that it is a chimera comprising F. balatonica and F. levanderi (Hirschmann), for which we provide new, expanded diagnoses. Chimera Type 2 refers to a genus defined by juvenile morphological traits that also occur in other genera. Analysis of Candoniella Schneider, 1956 shows it to be an artefact based on morphological traits belonging to juveniles of at least three genera: Pseudocandona Kaufmann, 1900, Fabaeformiscandona Krsti, 1972 and Neglecandona Krsti, 2006. Elimination of taxonomic artefacts is necessary to improve not only taxonomy but also adjacent domains of investigation like the ecology and geographical distribution of confused taxa. Considered in historical contexts, the creation and perpetuation of such accidental monstrosities may be attributed to social motivations as well as limitations of material, literature and communication.