Moor Frogs vary from 5.5 to 6.0 cm long, but can reach up to 7.0 cm in length.
Males can develop bright-blue coloration for a few days during the mating season (March).
Males not expressing the blue body coloration are sometimes subject to mating attempts by other males thinking it is a female.

1st, 2nd & 3rd photo: De Groote Peel National Park, The Netherlands, 23 March 2021
4th & 5th photo: Kootwijk, The Netherlands, 17 March 2015