Emilio! So excitable he spills the secret on accident. xD

This NPC cooked Christmas Dinner

Channah... but she might have burned it a little.

This NPC brought a casserole that they made themselves... but no one can tell what the globby monstrosity is, and no one's brave enough to try!

That would be Toymaker. 8D Good at toys, but his experimenting spills into his kitchen sometimes....

This NPC had to wash all the dishes.

I feel like this one would have to be a team effort. Vicky would do the baking and others would cook dishes to share. Nalin would bring fruits and veggies. At least two people would bring green bean bake.

Edit: Yikes, ninjaed twice! I'm way too slow. I stand by my opinion that Nalin is the dishwasher.

This NPC secretly hates peppermint.

Peeblo because it looks too much like him.

This NPC always shake their gifts to see if they can tell what's inside!

Cessy! It's such a kid thing to do. But so does Magnus when he thinks no one's looking.

This NPC always drinks a little too much eggnog.

Tesel strikes me as a shaker. Edit: and she strikes me as a tipsy eggnog drinker.

This NPC gradually sneaks snacks from the sweets bowl all day.

That sounds like Jeryck! to both!

This NPC got stuck wrapping all the gifts by themselves.

Mr. Mayor. He kindly volunteered every time someone complained that they didn't have time... and before he knew it, he was wrapping everything.

This NPC gave everyone the same mysterious gift... What is that liquid in the bottle? It smells like almonds and... copper?

Maybe Vicky? But I think she'd rope Mr. Mayor into helping.

Edit: We had nearly the same answer. I think Lance might try his hand at questionably homemade gifts.

This NPC never reads the cards they get.

The twins! Cause it isn't anything interesting. :P

This NPC wears reindeer antlers.

I want to say Afrodonkey, but no one can tell since his afro is too big.

This NPC accidentally broke an ornament this year.

Lise. It was an "accident."

This NPC told everyone they didn't want any gifts this year, but secretly hoped they'd still get some anyway.

That would be... Tesel when she was practicing. No one saw her though!

This NPC ate all the chocolate gifts

Vicky for both. I think she would tell people she didn't need gifts since she got so many for their wedding.

This NPC is never quite sure how to react when they open gifts.

Yumeh. He must be so confused. xD

This NPC stole all the gifts!

Nalin. People always get him floral things, fake flowers, ugly flower magnets... honestly he doesn't like any of it! He likes real plants, not floral kitsch. But he's too polite to let on, so it just keeps happening.

EDIT: Peeblo!

This NPC gave everyone gift cards.

That sounds like Lance. so busy with his job no time to shop!

This NPC can't wait until the holidays are over

Maybe Aimee. She seems a bit forgetful so maybe she got them all last minute.

Edit: Cain.

This NPC has to bundle up every year since they hate the cold.

That sounds like Lapis, coming from a warm island like Merkhet can't be easy with all this cold.

This NPC writes thank you cards for all their gifts!

Mr. Mayor, since that sounds very official of him.

This NPC loves snowball fights.

Lise. She's grumpy, but not rude.

EDIT: I bet Cain does! He pretends he doesn't, but he secretly likes them.

This NPC pulled the bows off of every gift they were given and stuck them to their head, where they stayed for the rest of the night.

Magnus for the snowball fight.

And Afrodonkey for the bows!

This NPC is Santa's best elf 8D

Yumeh, but completely by accident. Unfortunately for them, people thought it was cute and didn't help.

Edit: Cain is the best elf evar!

This NPC still writes a wish list every year.

Sounds like Aimee!

This NPC can wrap a gift in less then a minute.