Who's For Dinner? is episode 12a of Rocko's Modern Life. In this episode Heffer invites Rocko to have dinner with his family. Rocko accepts, much to Heffer's relief. When he arrives Rocko is stunned to find out Heffer lives with a family of Wolves.
Rocko is at his house talking to his mother. When he hangs up, he talks about how much he misses his family. He shows Spunky his photo album of his deceased aunt and uncle. Later, Heffer comes around and asks Rocko if he wants to come to his parents' house to eat dinner. Rocko agrees and when they get to Heffer's house, Heffer reminds Rocko that his grandfather despises wallabies, but it wouldn't be a problem since his grandfather is near-sighted.
As the two arrive inside, Rocko discovers that Heffer's family are all wolves. Heffer introduces his family to Rocko and his adoptive mother Virginia takes the gift Rocko was about to offer her and finds that it is an "udder warmer," which she puts on her head. While in the living room, the family get into a commotion and later watch home movies of their selves back in the days.
Afterwards, the family go to the dining table for dinner and voraciously gobble up a moose as Rocko watches in disgust. Rocko excuses himself to the bathroom and finds piglets inside the mirror cabinet. As Rocko returns to the table, Virginia asks him if he and Heffer have known each other for a long time. Rocko tells her he has, despite the fact that Heffer had never told him that he was adopted. Heffer overhears this and asks if that is true. Virginia tells him that he is and that the Wolfe family found him under a tree in Brandewind Farms. She also explains that he was skinny, so the family fattened him up by getting ready to eat him up, but then they grew to love him. Heffer asks what about his birthmark, then George tells Heffer to take it easy and Heffer asks is that even his real name where Peter tells Heffer that his father used to call him steak and George tells Heffer to sit down and talk to him because he's still his father. Feeling devastated, Heffer sobs and runs away.
He is later seen at Night Hawk Diner asking for another order of fries, but the bartender tells him that he has had enough. Heffer tells him that he will tell him if he has had enough and bites the bartender in the chest, attempting to eat the mustard stain on his apron, prompting the bartender to throw him out. Back at the Wolfe residence, the family and Rocko call everyone to ask about Heffer's whereabouts, but no luck. So they search for Heffer themselves. Later, Heffer, now more obese than ever, gets kicked out of another restaurant and rolls down to an alley. When he stops, he wonders what his real parents were like. He goes to Brandewind Farms and finds a tombstone. Thinking that it is his father's, a devastated Heffer weeps in sorrow, until his biological father's spirit appears and reminds him that it isn't his grave. The tombstone, instead, belongs to a "Big Wet Cat," who died about eight years prior. His father then tells Heffer that he isn't even dead, but living at Conoga Park with his wife Joyce. His father instantly rebuffs Heffer and disappears in thin air, breaking Heffer's heart as he continues to bawl. A farmer comes around and reminds him that his adoptive family is looking for him. Heffer returns to his house and says that the Wolfe family is his real family after all. George gives him a big hug, which causes the steer to retch (off-screen). Later that night, Heffer is seen with his family (as silhouettes) on top of the roof howling at the moon.
Joe Murray has stated that one of his favorite episodes is Who's For Dinner because Murray enjoyed the premise and the development of the concept of adoption for a character. Murray said that he partially based Heffer on an adopted friend and used his friend's emotions to sculpt Heffer's role and actions. George Maestri described the story as "terrific" and the episode as "funny and poignant." Maestri said that the episode added "a whole new dimension to Heffer's character" that was used "in many subsequent episodes."