"Ambergris" is the 18th episode of the fourth season of the American animated comedy series Bob's Burgers, and the 63rd episode overall. Written by Scott Jacobson, the episode sees the Belcher children—Tina (Dan Mintz), Gene (Eugene Mirman), and Louise (Kristen Schaal)—discovering a lump of ambergris, which they decide to sell illegally with the assistance of former bank robber and family friend Mickey (guest voiced by Bill Hader) upon discovering its high monetary value. Meanwhile, Mr. Fischoeder (guest voiced by Kevin Kline) brings in his neurotic brother Felix (guest voiced by Zach Galifianakis) to help Bob (H. Jon Benjamin) fix the plumbing system in his restaurant's bathroom. "Ambergris" originally aired on April 20, 2014 on Fox and drew an audience of 1.52 million viewers. Nonetheless, critical reviews of the episode from The A.V. Club and Paste were generally complimentary towards its humor and plot lines, with the latter review giving particular praise to Galifianakis' guest role as Felix Fischoeder. Plot While scavenging for washed-up items at the beach, Tina, Gene, and Louise discover a strange lump with a peculiar smell, which they keep. At Bob's Burgers, Mr. Fischoeder informs Bob that his neurotic brother Felix, whose inheritance has recently run out, will be "doing some of the landlording" around the restaurant. Bob then asks an uneasy Felix to call a plumber to fix the bathroom's faulty water system. Later that day, Tina researches on the lump, discovering that it is a piece of ambergris—a substance excreted by sperm whales and highly valued by perfumers—and can sell for up to $30,000. Despite the selling of ambergris being prohibited by law, Louise hatches a plan and conspires with her siblings to sell the ambergris on the black market with the help of ex-bank robber Mickey, who now works at the Wonder Wharf. Felix returns and excitedly announces his plan to completely renovate the bathroom and host an elaborate unveiling party, despite Bob's objections. Meanwhile, Mickey calls Louise—who is now unhealthily obsessed with the ambergris—and says that he will arrange a meeting with a co-worker known as "The Nose" (Dom Irrera), who can sniff the ambergris and confirm its authenticity. Louise meets with The Nose by herself and decides to cut Mickey out of his promised share of the money, despite her siblings' objections. The trade takes place, only for Louise to receive $12 rather than the promised $30,000; she finds a note from