I recognize the bottom two, but not the top one. Those uniforms look like The Orville but I don’t recognize that character at all. But I also never watched S3 and it’s been since they aired (5 years?) that I watched the first two seasons of that show.
Edit: Looks like I missed the comment saying who the top character is, which is from S3 of The Orville, so I guess I am out of the loop on this one.
The fact that 5 kids knew well enough about the OP’s vegan status to use them as an example meant that the person probably never shut up about it.