Season 1's “Communication Studies” features a casual Beetlejuice remark, and Season 2's “Cooperative Calligraphy” has another one. Then, in Season 3's “Horror Fiction In Seven Spooky Steps,” Annie nonchalantly makes a third reference, triggering the rule that Beetlejuice will appear if you say his name three times, and a man in a Beetlejuice costume walks by.