Entry in progress—B.P.
 
Wikipedia: Tapioca
Tapioca (Portuguese pronunciation: [tɐpiˈɔkɐ]) is a starch extracted from cassava root (Manihot esculenta). This species is native to the North Region of Brazil, but spread throughout the South American continent. The plant was carried by Portuguese and Spanish explorers to most of the West Indies, and continents of Africa and Asia, including the Philippines and Taiwan. It is now cultivated worldwide.
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North America
While frequently associated with tapioca pudding, a dessert in the United States, tapioca is also used in other courses.[9] Bubble tea, made with tapioca pearls, is gaining popularity in cities with large Asian populations. People on gluten-free diets can eat bread made with tapioca flour (although these individuals have to be careful, as some tapioca flour has wheat added to it). Tapioca is also used as an ingredient in the Canadian Daiya brand cheese substitute.
     
28 November 1917, Flint (MI) Daily Journal, “On Board the Mosquito Fleet” by Kennedy Boardman, pg. 32, col. 5:
We had “slumgullion” (meat stew), bread and coffee, and for dessert, “fish eyes,” the highly descriptive term given to tapioca pudding.
     
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Our Navy at Work:
The Yankee Fleet in French Waters as Seen by Reginald Wright Kauffman
By Reginald Wright Kauffman
Indianapolis, IN: The Bobbs-Merrill Company
1918
Pg. 6:
ANd, though you may understand “spuds” and guess that “red lead” is catsup, which it hugely resembles, and that “shoestrings” are—or is—spaghetti, I venture to doubt that your perspicacity would divine that “slumgullion” is beef stew; “railroad hash,” a mixture of “spuds” and large lumps of beef; “canned Bill,” canned corned beef; “Mulligan,” shredded Bill and onions, and that “fish-eyes” are tapioca pudding.
 
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October 1920, The Delineator, ‘The Slang at Smith” by Margaret L. Farrand, pg. 119, col. 2:
Tapioca pudding is known as “fish eyes.”
 
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The Real Boy and the New School
By Albert Edward Hamilton
New York, NY: Boni & Liveright
1925
Pg. 147:
He sits at table where, when tapioca is wanted, the request is made for fish-eyes and glue; where water is sky-juice and milk is cow-juice; where one slings the grease and laps up the suds and slings his teeth into the sinkers.
 
13 October 1935, Cleveland (OH) Plain Dealer, “I served in the C.C.C.” by J. Danner, Magazine, pg. 4, col. 7:
Among the common names for items on the menu are: “Fisheyes” (tapioca pudding), “slush-on-a-shingle” (creamed dried beef on toast), “blanched worms” (spaghetti or macaroni), “dishwater” (coffee).
   
8 March 1942, Sunday Times-Advertiser (Trenton, NJ), “Books and Authors,” pt. 4, pg. 3, col. 2:
(Review of Army Talk: The Language of U.S. Soldiers by Eldbridge Colby.—ed.)
For example, take the old phrase “fisheyes,” which is used to denote tapioca pudding. Even though used in mess hall, it is hardly army slang; it is boarding-school slang, Boy Scout slang, boys’ camp slang, even girls’ camp slang—in fact, actually universal ‘kid’ slang.