Merriam-Webster:
Wiktionary:Main Entry: sparky
Pronunciation: \ˈspär-kē\
Function: adjective
Inflected Form(s): spark·i·er; spark·i·est
Date: circa 1865
: marked by animation : lively <sparky children>
— spark·i·ly \-kə-lē\ adverb
The nickname of the horse, Spark Plug, in the Barney Google comic:Proper noun
Sparky
A nickname for someone who is lively and animated
Barney later made his way down South to Hootin' Holler, North Carolina (near Dr. Goodword's old stomping grounds) on November 17, 1934 where he made the acquaintance of the equally diminutive hillbilly Snuffy Smith, whose first act was to take a potshot at him..... he's the guy with the "goo-goo-googly eyes" in the 1923 Billy Rose song
... Barney made his debut on June 17, 1919, in a King Features strip with the ungainly title Take Barney Google, F'rinstance.
... Barney (who was about half as tall as the other characters) enjoyed horse races, prize fights and similar contests, and was nagged by "a wife three times his size" (as the song goes) for it. The strip enjoyed modest success during its first couple of years — and then came Spark Plug.
... On July 17, 1922, Barney happened to be standing on the sidewalk in front of the Pastime Jockey Club, when an argument inside got physical and a man came sailing out the window, knocking Barney to the sidewalk. Convinced this relatively soft landing had saved his life, the grateful victim made Barney a gift of a horse named Spark Plug — and that's when DeBeck's strip took off running.
Sparky's first race became one of comics' first national media events, eagerly anticipated by millions of newspaper readers. So great was the public's enthusiasm that DeBeck, who had been planning to retire the plug after that one storyline, made him a permanent part of the cast. Spark Plug was such a star during the 1920s that children who enjoyed the comics were liable to get "Sparky" for a nickname — for example, Charles M. "Sparky" Schulz, who grew up to create Peanuts.