These frogs are White's tree frogs, also known as Australian green tree frogs or dumpy tree frogs (rude), and are absolutely characters from a Studio Ghibli film. They don't seem to be very good at distinguishing food from a person's finger, but apparently, frog bites are slimy but not painful.
This one is somehow even cuter. Look at how he blinks and tell me that this isn't anime. When sleeping, he turns into the tiniest little frog loaf. I am not sure what species of frog this one is, other than adorable.
These little guys are common rain frogs and look like angry potatoes. They bury themselves in the dirt, sometimes sleeping for months at a time. This fellow was woken up from a long nap for a health check, and was not happy about it at all.
Previously: How do you pronounce "Ghibli?" If you're talking about Miyazaki's anime studio, there's only one way (video)
