This book investigates comparative constructional idioms of ugliness in Spanish, English and French from a Construction Grammar perspective, combining phraseological theory with a corpus-based methodology. It examines how patterns such as [más feo que X] and [feo como X] in Spanish, [ugly as X] in English or [laid dome X] in French  reveal both the productivity and creativity of language, and how they reflect cultural models of ugliness and expressivity across linguistic communities. The analysis identifies cross-linguistic similarities and differences in the formal structure, semantic variation, and pragmatic functions of these idioms, uncovering how meaning and form interact within the grammar–lexicon continuum. By addressing the notion of constructional equivalence and proposing a tertium comparationis for cross-linguistic comparison, the study sheds light on how constructions evolve, extend analogically, and reflect cultural models.The book contributes to research on constructional idioms, usage-based grammar, and corpus linguistics, offering valuable insights for scholars of cognitive and contrastive linguistics, as well as those interested in how culture encodes culture and creativity.