Daniel Belcher was a character in the demo stages of Bob's Burgers, as shown on the Complete First Season DVD set. He was set to be the oldest child of the family, but the crew felt like having the idea of two sons would not have worked well, so they changed the gender of Daniel and turned him into Tina. Since then, the character has been scrapped.
Along with similarities to Tina, he shared most of her lines in The Demo. The only difference is that he talked about his testicles itching, along with a small scene that was talking about his itchy crotch.
Daniel makes a cameo the Bob's Burgers comic Issue 5. He appears drawn on a letter in Linda's Letters where Linda is imagining an alternate universe of the Belcher Family and that Tina is a boy.