(european) Tree frog. Hyla arborea small ones 2-3 cm max. https://www.repiuk.nl/albums/new/#&gid=1&pid=005-864-imgp2372 https://www.repiuk.nl/albums/new/#&gid=1&pid=005-865-imgp2410 DA*300 Canon 500D close-up That wasn't the easiest combo but it's helps to keep a distance.