In English there are a variety of minced oaths, e.g. oh my gosh ("oh my God"), darn ("damn"), heck ("hell") etc. Similarly in Catalan one often hears ostres (esp. ostras) in place of "hòstia".
Are there any examples of this in Spanish? The only one that comes to mind is the very Alatriste-ish pardiez for "por Diós".