I´ve collected all the plushies of the lonely pinguin collection but I´ve didn´t received any achivement for it, why?

I've noticed it tends to take a few moments to register collection and wardrobe achievements. Go to your collection, then to the Achievement page, and it should pop up.

Sometimes (or always, if you're like me) you need to go to the Achievements page, click the Show Required Items button and then refresh the page, before it registers.

"Put a Spell on You " Achievement - Not being given

All show check marks, except "Gourd Witch Green Light," I thought I had already put it in my wardrobe, but I bought the item again and tried to add it to my wardrobe. Says It is already in my wardrobe. Site will not give me the achievement.

Yes, but the achievement still isn't there.

EDIT: Went back several times to achievements, and then the last check showed up... now I have the achievement. Thank you so much. <3

Glad it finally decided to work with you! Naughty achievements are stubborn sometimes!