A hagfish can turn a bucket of water into slime in under a second

When grabbed by a predator, a hagfish fires mucus and coiled protein threads from glands running the length of its body, which expand up to 10,000-fold in seawater into a suffocating slime cloud almost instantly. Predators that get a mouthful typically gag and flee, and the hagfish escapes by simply tying itself in a knot and sliding out.

— Douglas S. Fudge, Kelly H. Gardner, Valerie Trystan Forsyth, Christian Riekel & John M. Gosline, The Mechanical Properties of Hydrated Intermediate Filaments: Insights from Hagfish Slime Threads — Biophysical Journal, 2003