It's a tiny version of Giko! ...Or is it?
Chibi Giko (ちびギコ) is a separate character from regular Giko. He's more mature than Giko, and ends sentences with "～ﾃﾞﾁ"/"~dechi". Like Shii, he is a common target of abuse.
Chibi Giko and his dreivatives are usually portrayed as neotenous adults, similar to axolotls.
Damarekozo (ダマレコゾウ) is a strong-willed derivative of Chibi Giko. Its name comes from the phrase "黙れ小僧"/"damare kozo" meaning "Shut up, kid!"1 He's sometimes called "Reko" (レコ) for short.
Its 彡 is sometimes portrayed as wings that allow it to fly.
Chibi Shii (ちびしぃ) is a chibi version of Shii. Baby Shii is thought to have been derived from it.
Chibi Fusa is a chibi version of Fusagiko.
Gyaafusa-tan (ぎゃあふさたん) is a derivative of Chibi Fusa that begins all his sentences with "Gyaa". It started with AA of Chibi Fusa saying "Gyaaaaaah!" while being abused. The AA was edited to say "Gyaa, Fusa-tan's teeth" in a calm voice. No matter how much Gyaafusa-tan is hurt, he will always remain calm and say "Gyaafusa-tan's [body part]".
Fuu (房津) is the child of Tsuu and Fusagiko. Don't ask me how that works biologically.
Nirachi (ニラッチィ) is the child of Niracha Duma.
1This phrase was popularized by the movie Princess Mononoke, where Moro says it to the protagonist Ashitaka.
