Relying on Optimality Theory (Prince and Smolensky 1993) and Correspondence Theory (McCarthy and Prince 1995), this paper presents an analysis of the patterns exhibited by Spanish portmanteaus (e.g., [bɾuxéɾes] ‘mean women’ < [bɾúxa] ‘witch’ + [muxéɾes] ‘women’), which demonstrates that such playful word creations are not generated according to the same principles that govern the grammatical morphology. Instead, portmanteaus are created in the extragrammatical morphology (Dressler 2000), where they are subject to constraints that are ‘distorted’ versions of those found in natural language, and others that are exclusive to playful language. It is also shown that Spanish portmanteaus are endowed with a syntactic/semantic head, which is crucial in order to account not only for their syntactic and semantic properties but also for their phonological form. Despite their non-canonical structure, portmanteaus are subject to well-formedness and faithfulness constraints, which determine that only one of the many possible ways in which the source words may combine is optimal. Yet above well-formedness and faithfulness constraints, there is a principle of recoverability of the source words, which portmanteaus must always respect.