At No Way Out, Finlay and Postl defeated The Boogeyman and Little Boogeyman.^[14] Prior to the match was the first time Postl spoke, telling Finlay that little people scared him. Later that week on SmackDown!, Little Bastard pinned the Boogeyman with a jumping DDT, in a match pitting himself and Finlay against Boogeyman and Little Boogeyman.^[15]

On February 23, his name was changed to Hornswoggle on WWE's website and all references to the name "Little Bastard" were removed. The meaning of Hornswoggle is to swindle, cheat, hoodwink, or hoax.^[16] The name change became official on the March 2 episode of SmackDown! when Postl attacked JBL and Michael Cole. Afterwards, Finlay intimidated Cole and told him that Postl's name was Hornswoggle.^[17] Despite this, Cole continued to occasionally refer to Postl as "Little Bastard", as recently as WrestleMania 23; however, it is now thought to be merely nickname instead of his character's ring name. On March 30, 2007, he helped Finlay beat Mr. Kennedy by performing a senton bomb off a stepladder onto Mr. Kennedy, essentially copying Kennedy's move, the Kenton Bomb.^[1] SmackDown! announcers Michael Cole and JBL immediately referred to the move as the "Lepreton Bomb."^[18] During the Money in the Bank ladder match at WrestleMania 23, which Finlay was involved in, Mr. Kennedy hit Hornswoggle with a Green Bay Plunge off of a ladder when Hornswoggle tried to interfere.^[19] On the following edition of SmackDown!, Finlay attacked Mr. Kennedy after his match and challenged him to a handicap match with Postl as Finlay's partner.^[20] Before the match, Mr. Kennedy apologized for hurting Hornswoggle. Finlay accepted his apology and formed a team with Kennedy

Hornswoggle won the WWE Cruiserweight Championship after he pinned Jamie Noble in a Cruiserweight Open at The Great American Bash. He briefly ran across the ring as the bell was rung before going back under the ring making him an official participant in the match. The other participants and commentators were unaware that he was a participant in the match until the referee counted the pin and awarded him the belt.^[22] This made him the first little person wrestler to win a championship in WWE history. He also became the lightest, shortest, and youngest (21 years, 51 days) wrestler to win the Cruiserweight title. Hornswoggle then began a feud with Noble over the belt. The next week on SmackDown!, Hornswoggle retained the title when he defeated Noble by countout.^[23] He has attacked Noble in the following weeks by shoving a pie in his face^[24], spraying him with a fire extinguisher, pushing him into Kane (causing him to get chokeslammed), and locking him in a large box.^[25]

On September 10, 2007, in conclusion to the Mr. McMahon "illegitimate son storyline" on Raw, Postl was revealed to be Vince's son.^[26] Hornswoggle still made appearances on SmackDown! as well. Although his partnership with Finlay was quietly phased out, he still continued to feud with Jamie Noble. The Hornswoggle/Noble rivalry ended on the September 28 edition of SmackDown! when Acting General Manager Vickie Guerrero forced Hornswoggle to surrender the Cruiserweight Championship, citing that his status as Mr. McMahon's son and his diminutive stature would eventually jeopardize his well-being.^[27]

After the affair of finding out who the illegitimate son was, Mr. McMahon began giving Hornswoggle matches against competitors that were much larger than him. His reason for doing this, was that he was showing his son, "tough love." Hornswoggle was placed into a match against The Great Khali at Survivor Series. At the event, Khali defeated Hornswoggle by disqualification when Finlay attacked Khali on Hornswoggle's behalf.^[28] This was the first time that Finlay appeared together with Hornswoggle since the beginning of the Hornswoggle/Vince storyline. Finlay's attack on Khali started a feud between the two. At Armageddon, Finlay defeated Khali with the help of Hornswoggle.^[29]