To my knowledge, he pioneered what I call the "Badass Wearing Helmet Staring Down At You". (Unfortunately, it's not the most clever thing I can come up with at the time of this writing)
Good ol' Giménez was born in 1943 in Argentina. He took up industrial design (always a plus for great sci-fi artists) and then he traveled to Barcelona's Academy of Fine Arts (that always does the trick, doesn't it?)
He settled in Europe at the end of the 1970s where his art has been published in Italian, French and Spanish magazines, graphic novels and books. His collaboration with the likes of Carlos Trillo and Ricardo Barreiro gave the guy a lot of cred.
If you're old enough to remember his published work on the French mag Metal Hurlant, more power to you.
He is probably most well-known for his work in "La Caste des Méta-Barons", published by Les Humanoïdes, where he collaborated with some Chilean writer named Alejandro Jodorowsky. This epic series covered the origins of the powerful clan of the Meta-barons and a lot of other events I don't seem to remember.
The friendly looking Meta-baron...
Metabarons was the series that introduced me to the all that awesome European comic stuff that nobody seems to really appreciate.
... did not like getting cancelled.
It was brought in the States by Humanoid Publishing in collaboration with some other major publishers in the early 2000's (or noughties or whatever you want to call that decade) but from what I heard it didn't pan out so well.