Jeremiah is Constance's crush whom appeared in "The Monster of Phineas-n-Ferbenstein". He is the Jeremy lookalike in the Victorian age. He could be an ancestor of the modern Jeremy. He dressed as (or is) a vampire at the best monster contest.
- "The Monster of Phineas-n-Ferbenstein" (First appearance)
Since he complimented her at the "Best Monster Contest", it's possible Jeremiah likes Constance.