We're not just talking for fans of general giant monster and robot movies here. These valentines are a level of geek higher than that, intended to be received by somebody who already knows, for example, that there is a Kaiju in the movie named "Tresspasser" and will appreciated a joke based on it. Me, I didn't remember there was a character named Raleigh. I do remember Stacker Pentecost (a name which curiously got a pass from people who made fun of "Cypher Raige"), but have no idea if I just spelled it right or not.
These may be homemade, but Legendary Pictures linked to them on Twitter, so they are tacitly approved. And frankly, if you give someone a valentine with Ron Perlman on it and they like it, you have a keeper.