Ali Dee



Ali Dee is the alter ego of Mona Vanderwaal. During Spencer's stay at Radley she found out that Mona had hidden her nurse cap, CeCe Drake's visitors pass, and her own fake ID in a rocking horse. Spencer was led to the rocking horse by Mona's Map (which depicted the rocking horse as a star) as well as instruction from Alison DiLaurentis (possibly a hallucination).

Identity
It is unknown to the audience who exactly "Ali Dee" Is for sure. We do know that Mona Vanderwaal's face and identity are printed on an ID card to get out of Radley Sanitarium. She possibly used the name as a pun to Alison Dilaurentis's name.

Season 3
In "The Lady Killer", Mona leaves Radley dressed as nurse. Later, she is seen wearing a black hoodie and taking instructions from someone by phone. She goes to "A's" lair and reports someone, who also wears a black hoodie, that she changed plans. near the end of the episode, Mona is talking to another member of The "A-Team", who is revealed to be Toby. She tells him about her disappointment that the plans didn't work out as they should.



In "I'm Your Puppet", Spencer finds out about Mona's alter ego. She was led to the rocking horse in the children's quarters in Radley by a map made by Mona on a board game. Spencer also had a little help from Alison.