Rat-tailed Maggot

Rat-tailed maggots are the larvae of certain species of hoverflies belonging to the tribes Eristalini and Sericomyiini. A characteristic feature of rat-tailed maggots is a tube-like, telescoping breathing siphon located at its posterior end. This acts like a snorkel, allowing the larva to breathe air while submerged. The siphon is usually about as long as the maggot's body (20 mm (0.79 in) when mature), but can be extended as long as 150 mm (5.9 in). This organ gives the larva its common name. I have no idea what the stringy bit surrounding this larvae is, possibly a stray piece of plant root.
The most commonly encountered rat-tailed maggot is the larva of the drone fly, Eristalis tenax. I am uncertain as to this ones parentage though.