The study of unarticulated and onomatopoeic forms ahs not traditionally received much attention, although this field has sparked interest and curiosity, especially among researchers interested in comic books and those with a particular sensitivity for the problems of language. The number of published works related to this elusive topic is growing, and this article aims to offer a contribution to the study of onomatopoeia in comic books. The author investigates the use of onomatopoeia in comic books in Spanish in recent decades and compares translated with original production. To achieve this end, attention is paid to two different aspects, namely the strategies used by Spanish translators when translating onomatopoeia in source American comics, and the use and creation of onomatopoeic forms in original Spanish comics. Data comes form three sources: American comic books translated into Spanish, comic books originally written in Spanish, and results form a questionnaire on the use of onomatopoeia distributed to Spanish cartoonists and comic writers. The conclusions point to the fact that, since onomatopoeia show the same patterns and similar distribution in original Spanish comics as in those translated from English, it is difficult to ascertain to what extent onomatopoeia in American comics translated into Spanish are 'translated' or simply 'copied'. When English onomatopoeia are retained in translated comics, this may simply mean that they are not perceived as 'foreign'.