Tweeds is a young male mouse, with pale tan fur and thick black eyebrows.
He wears a teal dress shirt, a dark blue tie, beige sweater vest and pants with a teal handkerchief tucked in his left pocket, and black dress shoes.
Later, he is seen during the Feast of St. Squeaky, wearing armor and brandishing a wooden sword. He sword fights against his brother Nantucket, who is armed with a fondue skewer.
When the family begins to sing about the cat king, Tweeds sings about stabbing the tyrannical King Puss Puss and then pretends to run his sword through Nantucket, who collapses onto the table and throws handfuls of red confetti while the rest of Ralph's family cheers.
The next day, when Princess Carolyn and Ralph are leaving Stilton Acres, he is seen standing beside Nantucket, and waves goodbye to them as Ralph places the last of their luggage in his car.
- During Feast at Stilton Acres, Tweeds presumably plays St. Squeaky in the reenactment of his heroic defeat of King Puss Puss.