We bought this main engine and all the little caboose type silly pet attachments that go along with this mini lalaloopsy toy. It's so darned cute, but I would not recommend for kids less than 5 years old.
Pros's and Cons to it, here's my take:
The main train actually takes batteries (AAA's so make sure you have some around or buy them, we're a household of AA's so I had to make another trip!) it plays a really cute tune that you can't get out of your head, both my husband agree its one of the cutest noise singalong toys that we've probably had. My daughter played for a long time hooking up the little attachments and playing with the adorable pets that come with it, it takes some patience to hook up the little attachments, thats why I wouldn't suggest for less than 5 years old. it's really colorful but thats about as educational as it gets, not an educational toy at all. Once you have hooked up the extra silly pet attachments, (which are sold individually and tally up to a small fortune) the train actually powers the engine and all the cabooses follow it around the room, will only work on hardwood or vinyl floor, won't power very well on ceramic floor and forget it on carpet.
I actually had to return the first one as it didn't do anything, but second time's a charm...overall we like it, I would recommend it for 5 and up, probably a good toy to "build up" piece by piece due to cost.