
a life-sized replica/reconstruction of Diplocaulus, an extinct Devonian/Permian amphibian. 1 m square, 1 m long
and this is a close second:

a black mamba from a 300 x 17.5 cm rectangle, over 1 m long when finished - I made the scales in an inefficient way, i wasted a lot of the original length on them, i am planning to redo all the scales, which could potentially make the snake over 2 m long.