We report the first example of the synthesis and the "schizophrenic" micellization behavior of a multi-responsive double hydrophilic ABC miktoarm star terpolymer. A well-defined miktoarm star terpolymer consisting of poly(ethylene glycol), poly(2-(diethylamino) ethyl methacrylate), and poly(N-isopropylacrylamide) arms, PEG(-b-PDEA)-b-PNIPAM, was synthesized via the combination of atom transfer radical polymerization (ATRP) and click reaction. Containing pH-responsive PDEA and thermo-responsive PNIPAM. arms, this novel type of miktoarm star terpolymer molecularly dissolves in aqueous solution at acidic pH and room temperature, but supramolecularly self-assembles into PDEA-core micelles at alkaline pH and room temperature, and PNIPAM-core micelles at acidic pH and elevated temperatures. Most importantly, both types of micellar aggregates possess well-solvated hybrid coronas.