The stuff that these tricycles transport can be as different as night and day! Here are two examples:
This tricycle was transporting a gas cylinder at night along the national highway in Calamba. What a way of transporting, right? it's not the most ideal because the cylinder could get dislodged on a particularly bad bump... And probably explode. For some people though, this is the most convenient and the cheapest way of transporting such things. Traffic was not moving at the time because a container van trailer was being maneuvered into some weird configuration on the outer lane.
And here's another one. I presume that these colorful toys are going to be sold in one of the markets in Calamba. It's just nice to see something jolly while stuck in traffic on a beautiful morning. Who wouldn't smile after seeing Spongebob floating in the air instead of being under the sea, right? The traffic jam was caused by everyone going to the town proper taking the expressway as an alternate route while a bridge is being repaired.
I have yet to take a photo of a trike with a pig and a dog as passengers. But I've seen some.