Yep OS is right, Legos are totally non-toxic. I did a good bit of research on this.
On the other hand you go to Petsmart and buy those little superhero statues and apparently the paint starts bubbling off within a month (and then the fish mistake it for flake food and ingest it)
Ironic...
Thank you everyone!
Yesterday he got 6 zebra danios and a frog. I still have a future plan to move out those green cories and replace with dwarfs, so stocking-wise we are fine. Right now they are only an inch long.
Regarding the sharp parts - all of the "sharp" pieces are actually rubbery and not very sharp at all. I did consider taking them out (I assume you are thinking of the white teeth in particular) but I didn't find them to be particularly stabby. I'm keeping watch on the fish though for any signs of problems. Their health is obviously paramount.