I feel like there was some sort of achievement for having all the phugs in your inventory. Is this true, or am I imagining it? My achivements pages are bugging out (3-4 repeats of certain ones as I scroll down), so I can't find it.

Real achievement, or am I imagining things?

I don't believe there are any phug related achievements. I also did an achievement search ("phug") and none came up.

there isn't

but there should be

Yeah I wouldn't be opposed to having one. Maybe now that we have minion zoos, it could be for having all of the phugs in your collection.