Frappy is a neologism meaning, "frantically happy."
This comes from the 1980s comic strip, "Toby Juan: Hound of Decadence," where Toby's owner's name was Dave Frappus.
Frappy (adj); to frap, frapping, frapped (v). Synonyms include ham, cheeky, and in Spanish, chiflado. It nicely fills a void in the English lexicon where no other word quite captures the spirit of unprovoked silliness.
For example, when a puppy, for no apparent reason starts running around the house like a maniac. Or, when a newborn colt suddenly feels spunky and takes off, farting across the pasture. People can be frappy also, especially little kids when they are feeling silly and goofy. Frappy can also be understood as just plain, silly-cute.
"Look at that frappy little kitten, playing with that piece of string."
Or, "I just got a raise at work and I sure am feeling frappy today."