Squidy is a weapon which was first developed to enter a coding contest several years ago.
The challenge was simple: each contestant was to choose a distinct monster from the original Unreal, and develop a single weapon by using that monster as its model and skin, without importing any custom assets, only code itself was allowed.
The idea in the end was not only to have a contest (for fun), but to also have a new community weapon pack as a result.
Unfortunately however, the contest never ended and was abandoned and forgotten about, and some participants never finished their weapons.
This weapon was first developed and finished for that contest back in 2013, but it was now repackaged in order to contain its own mutators and configuration, so it can be freely tweaked and played with as any other standalone weapon mod.
As for the ultra gore mod shown in the video, you can download it here:
Moddb.com
Have fun! :D