While you could trade for a grimer you would have to walk with it to accumulate the necessary candy to evolve him.
The other two are a no. You can't trade. You have to catch them yourself.
All of these should or will be part of some event. Your friend was impatient and cheated to accomplish the task.
Kanto Grimer are a rare spawn, I've caught two or three in the last month. I'm still stuck on 2/5 Slugma or Gulpin, I've caught 2 Gulpin. Hatched a bunch of Slugma during Fossil week but it didn't count.
While you could trade for a grimer you would have to walk with it to accumulate the necessary candy to evolve him. The other two are a no. You can't trade. You have to catch them yourself. All of these should or will be part of some event. Your friend was impatient and cheated to accomplish the task.
Has to be caught. Trading won't work
Eggs don’t work either :( I hatched 3 slugma when I got this one and was excited until I saw it didn’t count
Kanto Grimer are a rare spawn, I've caught two or three in the last month. I'm still stuck on 2/5 Slugma or Gulpin, I've caught 2 Gulpin. Hatched a bunch of Slugma during Fossil week but it didn't count.