SummaryThree‐dimensional (3D) food printing is widely investigated in the food sectors, such as customized food designs, personalized nutrition, and simplifying the supply chain. This study aimed to investigate the rheological properties and filament geometry of buttermilk‐mashed potatoes (BMP) to print 3D animal‐shaped foods through a syringe extrusion 3D printing technique using BMP as the printing material. The rheological studies showed that the BMP made with different weight ratios of mashed potato powder to milk‐water‐butter (BMP 1:4, 1:4.5, 1:5, 1:5.5, and 1:6) showed shear thinning properties that were suitable for 3D printing. The addition of liquid component is helpful in decreasing the viscosity of the BMP to flow through nozzles. Furthermore, water holding capacity decreased with an increased liquid ratio. The BMP 1:5 was optimal with high accuracy in all nozzles, and the optimal nozzle was 21G. It represented excellent shape fidelity and geometry. BMP1:5 with nozzle size 21G demonstrated 103.3 ± 1.3% active ingredient content, accurate ingredient content in various sizes of 3D printed objects, and precision in weight. This study suggested that 3D printing based on BMP could produce complex‐shaped food patterns for further development and applications for active ingredient administration in children by a food base.