Size using a DK/light weight yarn and 3 mm hook:

Length (without tail): ~21.5 cm/8.5 inches
Length (with tail): ~ 28.5 cm/11.2 inches
Width (without fin): ~10.5 cm/4.1 inches
Width (with fin): ~25.5 cm/10 inches
Smaller width: ~3 cm/1.1 inches