lol, Well we used normal styrofom the paint was a hobby type of paint that your children can use so wich means that it is non toxic i hope,lol. I'am not sure the name of the tool that my husband used to carve it out but i will take a picture of it and post, mybe you guys will know,lol. When we first started out we did not have that trunk on there and we saw a picture of one that had one so my hubby glued the styrofom that was left over from when we cut it to fit our tank. Then with a razor knife cut out the big pieces that was not needed and then just started carving on it i can also post a picture of him carving on it
. But no we really did not run into any big problams, just one small glitch and that was cause we used spray achrylic in stead of paint. It did tend to eat some of the paint away but we just brushed over those spots again with paint, and i think when it did that it gave it a more natural look.