When you "leap at the chance/opportunity/offer", you eagerly seize the opportunity presented to you. There are several similar phrases that can convey this same enthusiasm and willingness. Some other synonyms to express the same idea include "jump at the chance/opportunity/offer", "seize the opportunity", "take advantage of the opportunity", "grab the chance/opportunity/offer", "embrace the opportunity", and "pounce on the chance/opportunity/offer". Regardless of the wording used, these phrases all convey the eagerness and excitement that comes with taking advantage of an opportunity that presents itself.