Gamakichi debut as a young orange toad with purple markings around his eyes, mouth and stomach. In Part I, he was small enough to fit on top of Naruto's head like Akamaru could fit on top of Kiba's head and wore a blue jacket. After the time-skip, Gamakichi has grown much bigger in size, though not nearly as big as his father, Gamabunta, but now Naruto can ride on his head and he can carry an adult human in the palm of his hands. He still sports a blue jacket.
In Part II, Gamakichi has not just grown in size but in maturity as well. Gamakichi seems to have a considerably large amount of knowledge when it comes to human-toad combination techniques and nature energy. Also, he seems to be on better terms with his younger brother, Gamatatsu, as shown by him no longer calling him an idiot.
He is rather funny, and has the mannerisms of a smart aleck. He is also often very condescending as well as light-hearted in most situations, preferring the levity of talk to the seriousness of battle. He seems to favour Naruto because he saved him from Gaara in his miniature Shukaku form. After he is summoned he tends to greet people by saying, "Yo".
Though his abilities have not been expounded on much in the manga, but in the anime, Gamakichi has shown a variety of techniques. He has been shown to be able to shrink his body size for infiltration purposes. He's shown the ability to use the Reverse Summoning Technique and summon Naruto to Mount Myōboku.
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