..yes, a bit like that!
This little underwater scene is made from an egg carton, coloured paper and tissue, old Christmas and Birthday cards + paint, scissors and the usual.
First, separate the top and bottom of the egg carton - the lid will be the base part that holds the eggs will be the rock and coral formation.
Get rid of the fastening hole by cutting a little cave opening for underwater dwellers. Paint your undersea rocks grey - put a small splodge of black and a larger one of white on a plate - mix them, but not too much, so you get some lighter and some darker bits - this makes the rocks look more realistic.
Cut a strip of coloured paper (or tissue), tall enough to stick out of your cut cone, and snip along the length of it, keep your snips quite close together and cut to about 1cm from the bottom, so you get a kind of fringe effect.
Roll it up and glue the bottom part into the cone. Press the top part with you hand to make the strands spread out.
For the colourful coral, use old or spare sponges.
Pull off chunks and then nip and pinch little pieces off your chunks to get a sort of pitted, coral effect.
Similar to the rocks, we used red and yellow paint to get a mix of colours on the yellow sponge and added dabs of blue paint to the green one.
Glue your coral onto the egg carton base. Use a glue gun or strong glue like UHU as PVA craft glue isn't so good with sponge.
Cut little simple fish shapes or any other sea creature shapes out of colourful, shiny old cards, and glue around your underwater scene.
We added a little egg carton crab, made from an egg carton cup - the eyes are hole punched paper circles glued on thin card strips, pushed through two slots on top.