Plutoniumidae is a family of centipedes. The type genus is Plutonium, so I’d expect the family to be Plutoniidae. The rule is broken if it would result in synonymy, such as the bee subfamily Dasypodainae being named after (not named for) the armadillo family Dasypodidae (which implies Dasypodinae even though there’s only one genus). But why is a centipede named Plutonium?
So I was inspired to look up the origins of the genus name and it was first erected in Cavanna 1881. Plutonium the element wasn’t named until 1941 so the centipede was named after Pluto, Roman god of the underworld, not the radioactive element. This makes sense as the first named species were blind cave dwellers from Italy.
A couple of non-animals are turkey tangle frogfruit (Verbenaceae, and oddly its genus is named Phyla) and pingpong bat fungus, which is in fact a mushroom, though it doesn’t look like one.