Q.Some new pups are coming up all yellow
I have many Agave plants and they all produce offsets , but one of my plants produces an occasional all yellow pup. Why is this ? What is going on with the yellow ones. I know I don’t overwater them and none of my other Agave do this.

Certified GKH Gardening Expert
This one may have a variegated sector. It's hard to say without seeing more of the plant, and knowing more about the care.
If this is the only plant doing so, then my best guess is variegation. If you transplant the pup and it still retains its variegation, then you may try and have it to produce pups. You may get some neat patterns down the genetic line.
Here is an article for more information on Agave: https://www.gardeningknowhow.com/ornamental/cacti-succulents/agave/growing-agave.htm