Black/green tadpole.
Lots of these around in April. Sometimes the trout seem to want fluorescent heads, sometimes they don't. This fly works well everywhere in fact and is quite handy in New Zealand, pretty much at any time of year. Not much good in rivers since the tail wraps.
Tying instructions:
Size 10 debarbed and leaded. Black marabou tail, one and a half turns of fluorescent lime green chenille.