Danny is a small dummy with black hair that is normally drawn as an upside-down tick shape, and a large mouth that is almost always smiling with large teeth and apparently no cheeks, as his lips receed past his teeth and gums. His eye colour varies between brown and green, and sometimes is even both. In real life, his eyes are brown, but has worn several different paper 'contact lenses' in green, black and a spiral shape. He wears bright red lipstick, often shown to be smudged or dripping on his right, and is sometimes shown wearing other makeup such as eyeliner, blush and nail pollish. He often is shown to be wearing a large red bowtie, but sometimes wears a smaller black bowtie. He has two main outfits: a black and white checkered shirt with multicoloured pockets or a light brown straitjacket. He is also sometimes seen wearing a shortsleved black tuxedo with a grey waistcoat, which is sometimes worn in adition to the straitjacket, and has been shown wearing several different one-off outfits. He normally wears black trousers, but has sometimes been seen wearing white trousers. He has long, knee-high socks sewn onto his legs and is normally shown to wear black shoes with the laces undone, however in real life he does not wear his shoes as they keep falling off. He is sometimes shown with a plaster on the side of his head or stitches running along his forehead. Occasionally, he is shown with a long, grey tail.
Danny is very loud and behaves in a very erratic way. He is incredibly loud and likes to talk a lot, even though he normally doesn't have much to say. He behaves and speaks in a very childish way, and often screams when he gets upset. He is motivated by food, his favourite foods being chicken nuggets and chocolate. He is also shown to be quite violent, attacking and attempting to eat other puppets. It is also suggested that he has succeded with some of these attempts, as Reggie's letter in Slappy's Visitor states that "he seems to find wooden dummies especially tasty". He is shown to have a very inflated view of himself, and thinks he is still a celebrity.
- He is a replica of Danny O'Day, a dummy used in Nesquik adverts in the 1950s and 60s.
- His brother, Jimmy, is from a dream Cynder Rush/SilverGriffinflare had.
- He plays a prominent role in Cynder Rush/SilverGriffinflare's murder-mystery story ELYSIUM, as he belongs to Reginald Maxwell Powell, one of the main suspects.