A young Amazon milk frog finds a seat on the head of an adult at the zoo in Frankfurt, Germany.

ok... must challenge this.... what about:
the most gluttonous green frogs on the planet?





then there's the green and gold frogs:


and the white-lipped frogs:

They sure are Kali!
The pics with tweezers is a disturbing site! Its a No No!
1. never use steel tweezers
2. never hold them horizontally when offering food!

Reason is exactly because they are gluttonous as you describe. they lunge forward to get food and if they hit hard enough can impale themselves in steel tweezers and do serious internal damage to their mouthes or further in.
Frogs teeth are virtually non existant and even big frogs dont hurt.
Fingers are best for hand feeding. If you must use tweezers, try to get some plastic ones and even then, always offer the food with the tweezers held vertically infront of the frog. this minimises risk of injury.

Just a tip for you. No doubt others have differing or no opinions about it, but thats mine

Nice pics!