Creature found on a beech, maybe

• One falling off the twig, having croaked
• Arboreal croaker
• Arboreal amphibian
• Arboreal amphibians usually having adhesive disks at the tip of each toe
• Two-thirds of grotto collapsed around rock amphibian
• Amphibian climber
• Noisy amphibian
• Jumpy amphibian with sticky feet

Wiktionary Word definitions in Wiktionary
n. (alternative form of tree frog English)