This trope is all about creatures (humanoid or otherwise) who are denoted as "people" by their use of accessories such as tools, regardless of the characters being otherwise nude.
A pet animal might commonly wear a collar, but would not normally wear a coin pouch, tools, a weapon or a timepiece. Accessories of that kind would normally be a clear indication of "personhood" for the wearer, regardless of the character being otherwise nude.
The heroic space explorer is on an alien planet which seems to at least be able to sustain life as we know it. Perhaps the explorer is a scientist examining a soil sample outside her space tent. Suddenly there's a noise and the explorer looks up to behold one of the weird native lifeforms staring at her from the edge of the clearing.
"I wonder what that animal wants?" thinks the explorer. Then she realises: The creature, although otherwise nude, is wearing a belt holding a small sack, a hammer and a dagger!
The heroic space explorer is about to make First Contact
If the character uses the accessories for their intended purpose, this would be an even more decisive indicator that the character is a person and not an animal.
This is a subtrope of Funny Animal
but this trope occurs when the being is initially presumed to be non-sapient by both protagonists and audience and the being's sapience is revealed by its artifacts.
Related to both Half-Dressed Cartoon Animal
and Accessory-Wearing Cartoon Animal
but this trope is not limited to cartoon characters and is limited to non-clothing accessories.
[[folder: Film - Live Action]]
- Chewbacca of the Star Wars franchise wears a bandolier over his shoulder, which helps visually affirm that he's a technology-using alien and not some sort of bipedal beast in spite of his only vocal sounds being grunts, growls and roars.
- Averted in "The Cat from Outer Space" (1978). An alien that looks like a cat is stranded on earth. His super-computer / communication device looks like a glowing cat collar so he is mistaken for a common cat.
- In the Honor Harrington universe, the Treecats of Sphinx (small, six-limbed arboreals) were originally thought to be nonsentient. It began to dawn on the human colonists that they were wrong when they were seen to use stone-age tools (chipped stone hand-axes and woven nets).
- In Alice in Wonderland the main story begins when Alice sees a rabbit with a pocketwatch and waistcoat and follows to investigate.
- In A. Bertram Chandler's short story "The Cage", survivors from a crashed starship (on a planet where clothes don't survive due to some aggressive fungus) are captured by aliens and put in a zoo. Attempts to convince the aliens they are sentient by making baskets or demonstrating mathematics fail. But when they build a cage and put an alien mouse in it... well, only sentient beings are bastards enough for that.
- In the Fuzzy novels, the first indication that the Fuzzies were sentient was their use of sharpened sticks to kill invertebrate prey.
- One of the countless hominids on Ringworld was a borderline-sentient species which, while unable to use fire in their aquatic habitat, did use flaked stone tools (a borderline example since it is never stated whether or not the species wears clothes).
- In Tarnsman of Gor Tarl meets a Nar, a member of the Spider People, who wears only a Universal Translator strapped to his thorax.
- Inverted in David Brin's "Uplift Series" when humans are considered inferior to whales and dolphins because we are unable to do things without using tools.
- In Anne McCaffery's "Decision at Doona", human settlers on a new world encounter a village of intelligent cats. Both species assume the other is pre-sentient due to the primitive living conditions in each other's colonies. The aliens decide the humans are intelligent based on a child's ability to play games.
[[folder: Film - Western Animation]]
- In "Lilo and Stitch", Stitch is mistaken for a dog after he looses his laser guns (despite having six limbs) and then Lilo later realizes that Stitch is intelligent when he does things like riding a bike and building elaborate models of San Fransisco.