Haystack appears in the miniseries, and is voiced by Lizzie Clarke.
Haystack is first seen inside her hutch in the barn, along with Clover, Boxwood, and Laurel. She is confused by the idea of freedom, but comes to like it when Clover explains it. Hazel, Fiver, and Bigwig attempt to free them, but fail. After this, the hutch is moved inside the greenhouse.
Later that night, Hazel goes in alone, and manages to get the hutch open. The four hutch rabbits start to wander around the greenhouse, as soon as they're let out. But then, Tab comes in and corners all five of the rabbits. Then, Bigwig and Fiver come to their rescue. The vile cat jumps up onto a shelf, and knocks down a vase, alerting the wife, who quickly recaptures Boxwood.
The remaining rabbits go up the stairs into Lucy's room, and jump out the window, ending up on top of the greenhouse. They manage to make it down and past the dog, and make a break for it. However, as they're crossing the road, the farmer drives up in his car. Laurel goes tharn in front of the headlights, resulting in her getting recaptured by the wife.
The farmer grabs his gun, and starts shooting at the rabbits, not caring one bit if he shoots Clover or Haystack, calling them a "blooming nuisance." He sees Clover in the bush, and attempts to shoot her, but Hazel knocks him in the leg to save her. This results in him getting shot in the leg. After the four remaining rabbits lose the farmer, Bigwig and Haystack go searching for Hazel, but can't find him. Fiver blames himself for Hazel's death, as he'd seen a bleeding rabbit in one of his visions, but didn't realize it was Hazel. Clover reassures him that only the farmer was at fault.
Later on, Haystack and Clover are taken back to Watership Down, where they discuss what to do without Hazel. Clover sneaks out while the others are panicking and bickering, but Bigwig notices her, and goes after her. She finds Hazel, but gets captured by Efrafan guards, leading Bigwig to infiltrate the warren. Hazel, Blackberry, Dandelion, Hawkbit, Fiver, and Bluebell go to wait for Kehaar, as he's their only chance of escaping, while Holly, Strawberry, and Haystack stay behind.
Two days later, the rabbits arrive back at the warren, with all the does from Efrafa, along with Clover, and another buck named Blackavar, who teaches Haystack how to smell to survive. She at first smells chestnuts, but then smells very strange rabbits. Holly and Blackavar realize that the Efrafans have tracked them down, and they start closing off their burrows. Although not seen, she is among the rabbits mourning the death of Captain Holly (killed by Efrafans while protecting Hyzenthlay).
She survives the war, and can be seen listening to Bluebell telling the story of Hazel-rah to a bunch of kits, several years later. It is unknown if she gains a mate, though it is implied that she settles down with Blackavar.