Horseshoe crab blood is blue in colour, due to the presence of copper. It's valuable because it contains an "amebocyte" used in the field of biomedics to identify bacterial contamination in vaccines and all injectable drugs. The energy generator in this movie, the imorium clustergram, has the same blue color as the Horseshoe crab blood.
Characters on multiple occasions brandish a katana or sword and refer to it as a "ninja sword". Ninjas didn't use swords, samurai did.
Writer/Director Pierce Berolzheimer explained in an interview in Sept. 2021 how he was able to make this, his first movie. "After college, I weaseled my way onto the set of a movie called Sun Belt Express (2014). I started as a lowly unpaid intern and by the time we wrapped I was a Co-Producer. Afterwards I was hired onto another film with the same team, after which they asked if I had a film I'd like to make, so we made CRABS!. That's the short version anyway."
Director Pierce Berolzheimer said that while many horror films include several scenes of nudity and sex, he didn't want to go that route. He only included the one nude sex scene on the beach early on because he wanted to subvert expectations by teasing the audience with those expected tropes, and then delivering on something a bit more heartfelt and a bit more rom-com instead. "I think a lot of horror movies rely on the sex appeal of the characters to gain your sympathy, and I wanted to play with that expectation while also avoiding it like the plague. With a title like CRABS!, it makes sense to expect naked drunken teenagers being debaucherous before getting their faces eaten by crab monsters, but I didn't want to make that movie. I wanted to tell a sweet first-love story about two friends, and also have some crabs."
Directorial debut for Pierce Berolzheimer.