故事板湯姆·赫皮奇、史蒂夫·沃夫哈德、勞拉·內茲格(英语:Laura Knetzger)、格雷姆·福克、查曼·韋爾哈根(英语:Charmaine Verhagen)、山姆·阿爾登、金瑞(Seo Kim)[1]、索姆雷·瑟亞馮、漢娜·K·奈斯特倫、肯特·奧斯本、亞當·穆托和亞歷克斯·森瓦爾德創作。第九季同樣也有一部迷你劇集〈拯救哇賽秘境(英语:Elements (miniseries))〉,講述阿寶、老皮、嗶莫回到哇賽秘境後發現整片大陸被四大元素瓜分,他們與冰霸王、貝蒂和腫泡泡公主一同試圖將大陸恢復過往。同樣特別邀請Alex and Lindsay Small-Butera(英语:Alex and Lindsay Small-Butera)和擔任製作。
該季以〈惡夢怪球〉為首集,僅獲得71萬觀眾的收視(比照上一季的結局〈島嶼大進擊:回歸〉的100萬觀眾收視,該季首映收視明顯下滑),且季終集〈真心換絕情〉的收視率也僅有85萬。該季同樣廣受積極的好評,迷你劇集〈拯救哇賽秘境〉在很大程度上受到好評。Lindsay Small-Butera憑藉擔任〈舊照片的回憶〉一集的製作,在第70屆黃金時段創意藝術艾美獎頒獎典禮(英语:70th Primetime Creative Arts Emmy Awards)上,獲得了黃金時段艾美獎的黃金時段艾美獎動畫節目最佳個人成就獎(英语:Primetime Creative Arts Emmy Award for Outstanding Individual Achievement in Animation)。2018年9月4日發行了包含整個季節的一組。第九季播出後曾發行數張DVD,收錄了其中部分集數。2018年9月4日美國首次發行了包含第八、九和十季內容的DVD套裝。而2018年12月19日澳大利亞首次發行單獨僅有第九季內容的DVD和藍光套裝。
^"Orb" was released through the Cartoon Network phone App on April 14,[2] the Elements miniseries was released for download via iTunes on April 18,[3] and "Abstract" through "Three Buckets" were released via the Cartoon Network phone app on July 14.[4] However, because this field specifically refers to episode airdates, the information here will denote when these fourteen episodes first aired on Cartoon Network.
^Adventure Time production staff. Adventure Time Returns on Monday, July 17th. KingOfOoo. Tumblr. July 7, 2017. (原始内容存档于July 19, 2017).
^Thomas, Paul. Exploring the Land of Ooo: An Unofficial Overview and Production History of Cartoon Network's Adventure Time. Lawrence, KS: University of Kansas Libraries. 2020: 292–293 [July 12, 2020]. ISBN 9781936153190. hdl:1808/30572. (原始内容于2021-12-12).
^Metcalf, Mitch. Top 150 Monday Cable Originals & Network Finals: 7.17.2017. Showbuzz Daily. July 18, 2017. (原始内容存档于July 19, 2017).
^Metcalf, Mitch. Top 150 Tuesday Cable Originals & Network Finals: 7.18.2017. Showbuzz Daily. July 19, 2017. (原始内容存档于July 19, 2017).
^Metcalf, Mitch. Top 150 Wednesday Cable Originals & Network Finals: 7.19.2017. Showbuzz Daily. July 20, 2017. (原始内容存档于July 21, 2017).
^Metcalf, Mitch. Top 150 Thursday Cable Originals & Network Finals: 7.20.2017. Showbuzz Daily. July 21, 2017. (原始内容存档于July 21, 2017).
^Metcalf, Mitch. Top 150 Friday Cable Originals & Network Finals: 7.21.2017. Showbuzz Daily. July 24, 2017. (原始内容存档于July 24, 2017).
^Adventure Time (Collection 14): Elements Miniseries. madman.com.au. [February 24, 2018]. (原始内容于2021-03-21).
^ 17.017.117.217.3Cartoon Network: Adventure Time: The Final Seasons. (原始内容存档于July 10, 2018).
^ 18.018.118.2Adventure Time - The Complete Ninth Season (DVD). Madman Entertainment. [2018-10-01]. (原始内容存档于2018-10-01).
^ 19.019.119.2Adventure Time - The Complete Ninth Season (Blu-ray). Madman. [2018-10-01]. (原始内容存档于2018-10-01).
^Adventure Time production staff. AT Season Eight. KingOfOoo. Tumblr. January 9, 2017 [July 2, 2017]. (原始内容存档于2017-11-02).
^Muto, Adam [MrMuto]. Yes. The official season divisions seem to have moved around but when we made those episodes we approached them as the end of Season 8. October 2016. (原始内容存档于July 2, 2017) –通过Ask.fm.