My Eco-Complete came complete with

[mrzap]

Some sort of mini looking earthworm

Once I setup the tank I started looking at the gravel and there some some sort of worm halfway buried poking his head at the substrate. Very small skinny and brown with two little things poking out one end.

I think its pretty cool having an underwater earthworm in my tank that managed to survive being bagged for quite a bit of time. I'm just afraid someone will tell me its the rare parasitic amazon river deathworm that will eat my fish and then come after me

Artist rendition below

[mrzap]

Found a few more tunneling away

[travis simonson]

That is cool. I'll bet fish will enjoy them but you really should make sure they aren't some sort harmful pest. I know there are some sorts of larvae (dragonfly?) that can eat your smaller fish. Hopefully someone with more knowledge will chime in. Good luck

[BillD]

Looks like a millipede or some other similar type of insect. It is not a worm. the water will drown them, or you can remove them.

[mrzap]

They don't have legs like a millipede and they definetly wriggle around swimming like a worm.

I found some that got sucked up into the filter and I took a pic

[CompMage]

Don't know that you need to worry about your fish to much with them being that big, taste stack. But for your plants.. they could be some kind of grub.