This page contains information regarding Star Trek: Picard, and thus may contain spoilers.
Number One was a male Pit bull dog and Jean-Luc Picard's pet in 2399. During Picard's retirement, Number One lived at Château Picard, sleeping on a mat in Picard's bedroom and accompanying him in the vineyard. Picard used French when speaking to the dog.
Dinero, who plays Number One, is a rescue dog, with little previous film experience. "Remembrance" director Hanelle M. Culpepper described DeNiro as "very green" (that is, inexperienced) and "a challenge sometimes, but super, super sweet." Michael Chabon agreed, saying, "He was the sweetest dog. He was not a great actor." Culpepper noted that Number One was present in more scenes in the original script than in the episode as filmed, Culpepper noting, "We both agreed, let's leave the dog out of this one." (TRR: "Remembrance")