Instructions:
Head
Using 4 mm needles and green double knit wool, cast on 25 in green
Start with a K row and SS 4 rows.
(K3, inc) repeat to end
SS 7 rows
(K2 tog) repeat to end
Purl
(K2 tog) repeat to end
Purl
B & T tightly

Eyes (make 2)
Cast on 4
Inc knit-wise into every st
Purl
(inc, K) repeat to end
Purl 3 rows
(K2 tog, K) repeat to end
Purl
(K2 tog) repeat to end
B & T tightly

Making Up:
Sew up the head. 
Pull up the eyes tightly, let them fold naturally in half, and sew to the head as illustrated. 
Add your googly eyes, a stitched mouth, a length of red ribbon for the tongue and a small spider made by knotting some wool scraps.