The Nanigans consist of Fizz (one of the main antagonists of Enter Sammy Space-Time) and his relatives. Notice that "Nanigans" is borrowed from the word "shenanigans", which is a fitting term for what Fizz and Mugs are usually up to in the series.
Born in 1999, Edward "Fizz" Nanigans is a 15-year-old boy who usually bullies Sammy at his school. He is addicted to pop, and almost always is carrying a soda can with him, similar to his grandfather with coffee mugs. During Enter Sammy Space-Time, he and his grandfather attempted to extract Sammy's Time-Manipulation Ruby from his forehead using his father's OEC (Object Extraction Claw), but ultimately failed. Fizz, like his grandfather, is bullyish, but is more childish and spoiled than his grandfather was at his age.
Fizz's father, Dennis Nanigans, is an experienced scientist/inventor, only to have his skills wasted on his greedy son, whom orders his father to construct gadgets/inventions for his own purposes.
Fizz's mother, Nicole Nanigans, appeared in Enter Sammy Space-Time as a minor character. She is enabling and a good cook and has been ordered to stay out of Alberqueque for this reason, and seemed to get along with her husband. However, it was revealed by Fizz that she typically doesn't like it when his father "lets him down".
Theodore "Mugs" Nanigans is Fizz Nanigans' grandfather, and the father of Dennis Nanigans. He was born in 1939, and is 75 years old as of the events of Enter Sammy Space-Time. He discovered Sammy was a time-traveler back in 1954 along with all the other Pensacola civilians, and attempted to extract Sammy's Time-Manipulation Ruby (which would've most likely killed Sammy in the process) in 2014 using his son's OEC (Object Extraction Claw). His plan ultimately failed, and his whereabouts in the current timeline and time period are currently unknown. Mugs is very bullyish and demanding, and is even described as "thuggish" in Enter Sammy Space-Time. One of his gang members even hinted that he was somewhat dishonest (unintentionally).