In the intergrowth structure of the title phase, the geometrical flexibility of the TiNiSi type and the packing efficiency of the ZrNiAl type are simultaneously realized, while securing also the preferred tetrahedral coordination geometry of both Mn and Cd atoms. Possibly, these typical features of the LaNiAl type may be critical for the system to remain structurally stable upon temperature or chemical pressure driven rare-earth (here Eu) valence fluctuation as observed in the solid solution CeRu1-xPdxAl for instance. Therefore, the magnetic and structural phase transitions of the title phase should be thoroughly investigated.