Yoofus Lightpaw was a kleptomaniac water vole who was well-versed in woodland lore. Though he was unfailingly kind and generous and good natured, he was also prone to stealing everything and anything he could get his paws on. He was the husband of Didjety Lightpaw, who scolded his ways but was secretly proud of her husband's talents.
Yoofus' first known act of thievery in Rakkety Tam was stealing from the vermin camp of Gulo the Savage's horde of a hundred white vermin. He pilfered a curved sword from Captain Urfig, and also took the banner of Squirrelking Araltum and Idga Drayqueen. He made off with these, unwittingly leaving behind a trail which resembled that of a wolverine. Gulo thought it was Askor and followed. Yoofus noticed and began leading the vermin in circles.
He ran into Rakkety Tam MacBurl, Wild Doogy Plumm, Ferdimond de Mayne and Tergen the Goshawk, who were immediately suspicious because he had the banner which they were searching for. He told the squirrels that he would give them the banner and help them rescue the kidnapped maidens, Sister Armel and Brookflow, who were in the claws of the vermin, in exchange for Rakkety Tam's claymore. Tam agreed, but didn't take the flag yet. He told Yoofus to go with Ferdimond and Tergen to Redwall Abbey.
Yoofus sneaked out of the Abbey with Tam's claymore and the flag of the Squirrelking, but he did not get far. Tam's patrol bumped into him (actually Skipper of Otters dove into a pond and retrieved the watervole by the tail, who had been hiding). Yoofus told the patrol that he had spied on Gulo, and that Gulo's plan was to attack the Abbey.
Tam's patrol had a skirmish with Gulo's horde, after which Doogy, Ferdimond and Yoofus went off to the north. Gulo sent Dirig, the only ermine Captain in the horde, after them. Yoofus cleverly led them into a clearing which was actually a swamp. Then the three met up with Log-a-Log Togey of the Guosim, who were friends of Yoofus'.
Tam formed a plan which involved leading Gulo and his vermin into a grove of pine trees where a bunch of crows roosted. Doogy and Yoofus did not take part in this plan, for they tripped and fell before entering the grove and were left behind. Yoofus decided to go back and plunder the vermin camp while Gulo was gone, and for once Doogy agreed. Yoofus stole the drum which Lady Melesme of Salamandastron meant to send to Redwall, which Doogy didn't approve of.
The two were taken captive by a gang of vermin led by a weasel, who were living in the dormouse family of Muskar Muskar and Lupinia Muskar, who knew Yoofus but somehow did not know he was a thief. The vermin gang was forcing the dormice to cook for them. Doogy and Yoofus sent the dormice outside, then set upon the vermin ferociously. The whole gang was killed.
Doogy and Yoofus stayed overnight at the Muskar family's home, but in the morning Doogy discovered that Yoofus had bolted, taking Melesme's drum and his own dirk, in addition to the vermin gang's raft. Doogy and Muskar Muskar followed Yoofus back to his own home, where they met Yoofus' wife Didjety.
Yoofus made the age-old thief's excuse, "I was taking care of them for you", and Doogy took his dirk and the drum back. Doogy spied Rockbottom the tortoise, and recognised him as the Walking Stone which Gulo was looking for! Doogy insisted the tortoise be brought to Redwall. Yoofus, Didjety and the drum accompanied him.
Yoofus tried to lead them to Redwall by waterways and sidestreams, but got them hopelessly lost. All three lost their patience with each other, and in the end it was Didjety who was leading them. Doogy noticed that Yoofus was eying the drum, and was suspicious that the volethief planned on stealing it.
When they finally did get to the Abbey, Wild Doogy and the drum were taken captive by Gulo and his horde. Yoofus, Didjety and Rockbottom (or the Walking Stone) just managed to get into the Abbey, and were watching safely while Tam had his famous single combat with Gulo.
After the vermin from the Land of Ice and Snow were vanquished, Skipper discovered Tam's claymore and the banner of Araltum, hidden where Yoofus had found Rockbottom (Walking Stone). Doogy took it, because Gulo had been fighting with his old one and it was destroyed, and Tam now fought with the Sword of Martin. Yoofus and Didjety returned to their home safely, taking with them the tortoise.