Mocha lands at #99 with 1,006 entries, and like Rusty just above her, the name is doing literal descriptive work. Brown dogs and brown cats. Chocolate Labs, brown poodles, brown tabbies. The name is a color first and a coffee reference second, and most owners would tell you in that order if asked.
The food-name register
Mocha sits in a coherent food-and-beverage naming pool with Cocoa, Oreo, Peanut, and Mochi. These names share a register: warm, casual, slightly playful, almost always landing on smaller animals or animals in family households with kids. Mocha is the most adult-coded entry in that pool, partly because coffee is an adult drink and partly because the two-syllable structure feels less childlike than Cocoa.
The breed and species spread is wider than Rusty's. Mocha works on dogs, cats, and rabbits at roughly comparable rates. Color names that scan as food rather than as raw color tend to travel better across species, which is why Cocoa and Mocha outperform Brown or Tan in the rankings.
One counter-reading on the cultural texture
Mocha is also the name of a city in Yemen and the historical origin point of the coffee variety. Almost no pet owner picks the name for that reason, but the geographical history adds a quiet layer of texture that some owners find appealing once they learn it. The name is one of the few in the food register with a real-world historical anchor.
For owners who like the warmth of Mocha but want a different sound, Honey and Cocoa are the closest neighbors. Browse the main pet rankings for the full food-name cluster.