0-3 mo: approx. 3 ¼” long, x 3.2” tall
3-6 mo: approx. 3 ¾” long x 3.4” tall
6-9 mo: approx. 4 ¼” long x 3.6” tall (pictured)
9-12 mo: approx. 4 ¾” long x 3.8” tall
12-18 mo: approx. 5 ¼” long x 4.0” tall