Magicant

Ness finds himself in a very familiar place.

Also it looks like some giant Pop-Tart monsters thew up everywhere.

Walk around and you'll find several amenities. Be sure to optimize your inventory now because you're headed towards another boss.

There is a store that sells Magic Puddings which is quite spiffy.

Your sister can also give you things that have been stored with Escargo Express.

Make sure you have the Franklin Badge and/or as many Bags of Dragonite (if you've been saving them up) as you can with you!

You may notice the three flowers at the bottom of the first section of Magicant.

It's no secret that Toby Fox is a fan of Earthbound. So it may be no surprise to find what looks to be a very familiar EarthBound character in Undertale.

After you've got all the items you need, go to the Flying Men's house.

If you ask, one of them will join you. They definitely help but probably wont last too long.

Make your way through the area carefully. If you're level is not very high you'll struggle a lot with some of these enemies since you don't have the full support of your party.

Several great items can be found throughout the area. Make sure you have a few open slots for these.

Check the map for locations.

You will come to a vine in the middle of the upper section of the map.

This leads to the next area.