The following is my incredibly dumb personal theory about Mr. Grizz. Do not steal. Or do, who cares?
Mr. Grizz is a Salmonid. I know, I know. It seems absurd but it's the truth. He's some Chum, or Smallfry even, who got tired of being on the low end of the totem pole and sold his people out in the name of good old capitalism. He's taken on the avatar of a Salmonid death god and now he's selling their resources to the inklings.
This is why his shop is a sketchy mystery. This is why he only communicates via a bear-shaped radio. This is why he knows so much about the various types of Salmonids.
But as long as he keeps paying me, I don't give a squid.
(I apologise for how long this is in advanced. Also I'm sorry for all the spaces and gaps, I role play so that's just how I type, in paragraphs)
Sorry I'm late to the party (legit just made an account just to reply to this) I'm a role player and me and my friend come up with weird *** theories to go into our Roleplay's Alternate Universe Version of games.
And after she went to sleep I was just looking at some fanart and I found this
(I inserted a file, idk where it will be when I post this, I legit made this account minutes ago) and since it's a fish versions it got me thinking
"Huh what if Mr Grizz was a Salmon? That would be interesting for roleplay."
So then I spammed my friend with a ton of links to theory stuff so we could talk in the morning, heres a link to something else I found on the theory of what Mr Grizz is:
https://gamefaqs.gamespot.com/boards/200279-splatoon-2/76780703
So scrolling through some links on google to theories I found this and I was like "OMG SOMEBODY HAS THE SAME THEORY!" so they I read through all the replies and stuff and I found everything really interesting.
So here is what I originally thought was Salmon-Grizz's motives:
I always thought Mr Grizz was kinda evil. Since I was role-playing my character Shadow B who was a shy scared demonic thing, I was pretending to be terrified of salmons and Shadow was very cautious when he did the first test-thing that tells you how to do your job.
Shadow B didn't trust Mr Grizz because:
He was a f* bear radio, he doesn't explain why he needs the eggs, he didn't explain how this is making Inkopolis better, why Salmons are so hostile, when you start the game the Intro Guy says the place looked shady, Inklings/Octolings can get hurt while doing their jobs, Mr Grizz didn't seem to care if anybody got hurt, he doesn't pay you much for health insurance when you get a Crew-wipe, he skips over reading the manual and my friend had to explain how to read it to me cause I didn't know you could read it, he doesn't let you leave unless everybody is injured and there is no hope of getting all the eggs or you already "Survived" your shift, and I can't think of anything else this is long enough already.
Because of all that ^ when i found the fanart of Fish-Grizz it could make sense, it's all a scheme so the Salmons can slowly take over and Mr Grizz is giving you false hope.
Now somethings don't make sense, why would he setup a business that informs inklings/octolings how to fight Salmons if they probably wouldn't know before GrizzCo? I don't know, I was gonna talk about it with my friend but she is still asleep, I've been doing this for like and hour, so maybe someone here has an idea to build on the Scheme Theory?
Anyway that's all I'm typing this is long enough, again I'm sorry for the spacing (it's how I rp so now it's just how I type) and I'm sorry for how long this is.
Ima just quickly see if i can copy and paste Fish-Grizz where I wanted it just in case it doesn't go there when I post dis)