A scoubidou crocodile.

You need about 9 strands of scoubidou, (the 80 cm or 1 meter size.) If you keep your knots a little loose maybe more. If you want a lifelike animal use all greens you have at hand. You are likely to need more strands than the greens you have, you can use yellow, brown, gold or black. The color you start with is going to run out before you are finished, put three strands of this color to the side, for use later on.
Start with two dark greens, they may be different colors. Place them as they are in the first picture, tie a crown knot, the second picture. You may need a little help, ask a friend to hold a finger on the crossing. Make the next knot the other way round, the next picture. Make a total of four knots. Make a next knot but do not tighten, put in a new string and then tighten.

Tie two knots with six strands, this is called the lengthened crown knot, going the other direction each next knot. In the third knot you ad a new string again. Make three knots with eight strands, in the next do not tie the middlemost two strands but let them stick out from between the longer strands. Tighten this knot real well, as you do with the next two. Now go on tying with all strands, again for three knots.

If you want to give the crocodile legs, take one strand you had put to the side, cut it in four. Place them into your work by treading them through a loop, at the side/bottom of your work, before tightening the knot. You can do two at a time or one on each side now and again in the next knot (looks better.) Pull softly on the leg strands to check they do go around a loop. When making the legs, put also an extra strand in the middle of the body.
Tie one or two knots with the ten strings for the body to fix the leg strands. Then make the legs, I just make the crown knot turning, (the first knot on this page over and over again.) Six knots gives nice legs, tighten the last two knots really well. If you work with the special hollow scoubidou strands you can just cut the strands short, if you work with normal string, use a little glue to fix the strands before cutting.

From adding the last new strand make 14 knots before starting the hind legs. When you ad the strands at the side, take the middle two strands out in between the long strands, taking them out of the work. Tie two knots, cut the strands taken out short and tie the hind legs. Tie another knot. Take the next two strands out and tie a next two knots, cut the ends and tie another knot. Go on till there are only four strands left. If at the start of the tail one strand is too short you can tie the tail out of three strands, it two strands are short either replace them with on of the strands you should take out, or put one new strand in. The tail should be 12 knots long. Tighten the last two knots real well, if working with scoubidou cut short, working with string, use glue and then cut short.

If one end run short you can place a new strand along the left over bit and tie them together for a few knots. If they are the longer one in the lengthened crown knot, (the long ones in the pictures on this page,) one knot will be enough. You can also have a strand in the middle of the knot (like when taking out strands) and exchange it with the short strand.
If you are afraid the knot will get undone when you cut short, leave the work overnight and check the knot the next day. When working with the special scoubidou string if the knot has stayed tight it will not come undone any more, and you can cut at less than one mm. If in doubt or working with other string use glue but check on a leftover piece of string because some glues melt plastic.

Have fun.