Age group(s) for this birthday party activity:
Preschool and Younger
Elementary School

Birthday party planning information:
Thomas the Tank Engine and Friends have entertained several generations of fans: first in the collection of Stories, then in with video, and with video clips in the TV series, "Shining Time Station."

Related party ideas can be found in this list under the heading "Train Party."

But Thomas and Friends are special trains.

For the truly ambition cake decorator, the Wilton cake deco. supply folks have crafted a Thomas cake pan. It utilizes the paste colors, and a Star tip. Those of us who are losin' Wrist cooperation for that much effort can simply frost a basic birthday cake and put Train type toys on the top of it, with colored sprinkles. Black licorice can make a "track," if you desire. New Thomas cars can be put on the cake, and/or Sir Topham Hatt and Lady Hatt, conductors, or other Thomas friends.

You might also experiment with creating a Train shape by baking a 9"x 13" single layer for the engine, cutting part of an 8"x8" cake for the cab, and having Cupcakes or Oreos for wheels! Rectangles of cake can serve as Cars, with similar wheels. One might also try going 3-Dimensional with Loaf Pans for engine and cab, placing wheels on the Sides.
The beauty of it is, Thomas fans believe in Magic, so whatever you create (or buy at the bakery ;-) will be pleasing!

If you will be serving more than cake and ice cream, you could set up card tables in a line, and call it "the dining car." Keep it simple. (The conductor is here, with the Pizza! Yayyyy!!!) Serve soda pop or a "spritzer" (apple or grape juice combined with Sprite or 7 up), in sturdy glasswear or plastic stemware. Have matching tablecloths on the tables, folded napkins, and a Rose in a vase. (Well, it can be a plastic cloth from the dollar store, paper napkins, and a silk rosebud; we're going for a Look here ;-)

Thomas cups or clear cups will be wonderful for individual servings of vanilla ice cream. Place them in a tray, cover with foil or plastic wrap, and place in the freezer until serving time, when they can be "waitressed" in to the "dining car"...

Other suggestions or comments:
Games: pitch beanbags or rolled socks. Black socks look like lumps of coal! Toss them into "Sir Topham Hatt's Hat," or a "Smokestack"...which prior to the party was a coffee can or bucket, now transformed by poster board/construction paper, tape, etc.

One of the popular Thomas stories concerns the time Thomas ran low on water, and was filled with river water, using a bucket. Although he then had water in his tanks, something was clogging up the works for making steam. Upon examination of the situation, it was found that Thomas had Fish in his boiler. Everyone joined in a Fishing Party, to get the fish out of Thomas' boiler, and then they had a dinner of Fish and Chips (which would be another option for your dining car ;-). You could read the story, and set up a Fishing Booth (put a curtain in a doorway or hallway, using a spring-tension curtain rod. Use Dowels for fishing poles, attach String, with Clothespins at the ends. Kids cast their line over the curtain (one at a time; mind that they don't poke each other w/casting!), and someone behind the curtain attaches a small prize or a piece of candy w/the clothespin. If you can't think of oodles of prizes, use Gummy fish, frogs, etc, in a variety of colors and flavors, and kids will get different things each time.

Have some Music to Move to! Trains are popular now, so Train music is available. There is even a video collection of Songs from the Thomas series, sure to be a hit with a Thomas fan. A train songs tape/CD with Cajun flavor is "Choo Choo Bugaloo." A more mellow collection, perfect for playing with wooden trains on the carpet, is John Denver's "Train Songs." And there are always classics; look for collections that feature "Wabash Cannonball," "I've been Workin' on the Railroad," "John Henry," "City of New Orleans," "Atchison, Topeka, and the Santa Fe,"...the list goes on n' on, like a train...anyway, when you got Music, you got Body Movement, and Fun! If you are Brave (or know someone who is), the sheet music is available, and you can add live Guitar or Banjo music to the dining car.

There are Cardboard Bricks available that are the size of Real bricks. These would be Xcellent for a Team Relay of "bricking Henry into a Tunnel." Henry was the engine who didn't want to spoil his lovely paint, and refused to go out in the rain, blocking access to a tunnel, thus he was Bricked into that tunnel as a Lesson (and removed later; it's a happy ending). Have 2 teams, each with a "Henry." Given an equal number of blocks, see which team gets Henry bricked in fastest. Let each child have a turn as Henry, and several turns as Builder.

There is a "Thomas and Friends Party Game," which I haven't seen, but it's based upon Bingo, so it shouldn't be too hard to set up n' manage, and would also be fun Any ol' day.

Conductor Hats and Train Whistles are the most awesome of take-home things, or small Thomas books, which range from board books to Easy Readers.

Ordinary objects can be Fun with Thomas and Friends stickers attached. You can apply a sticker to a new bar of gentle soap; paint the sticker Twice with clear nail polish, overlapping slightly at the edge of the sticker. Allow to dry between coats, and then overnight. Wrap in tissue, and Label as soap! Thomas Tubby fun.
The sticker should last as long as the soap does!
My son used to line up laundry baskets and apple boxes to make his own "trains". Empty, or full of something, made no difference to him...

I'm sure parents of train-lovin' kids have even more party ideas related to Trains in general, and Thomas in particular ;-)