Figurine Pranks - Need Ideas

[The Omnissiunt One]

Nice videos. I've got a few suggestions:

1) Blu-tack little red eyes onto the ducks, and have them staring outwards. Or, blu-tack a bit of black fluff on their heads and give them afros. Hopefully, blu-tack wouldn't spoil them, and would hence avoid your housemate's wrath.
2) Have one at the bottom of a bowl or cup full of water, with a Lego brick tied to it with string. The others could be standing at the edge, looking suspicious (somehow).
3) On a similar note to 2), blu-tack a pencil upright, with another pencil attached to it horizontally. Then, hang a duck by its neck with string. Eh voila! You have your own gallows!
4) Stick little swastikas on them, and have them goose (or should that be duck?) stepping along the kitchen counter, in a line.

Nice ones. Number 2 sounds like the one that would be easiest to do as far as having the props goes, except for the Lego part. The ducks are usually on an open shelf above a counter, so if one is dead at the bottom of a water filled bowl, the others can look down at the scene from there. If I carefully draw (with something like a nonpermanent food) little grins at their mouths, that would look like maybe they pushed/body-dumped the other one.

I'm not sure what blu-tac is, but it sounds like it might be the same as what was called sticky-tac when I was a kid. It was a sticky putty-like substance used as a temporary adhesive that leaves no residue when removed. In school it was used to put papers up on the wall. Does that sound like the same stuff?

That does sound like what you're describing, yes. From Wiki: 'Blu-Tack is a versatile, reusable putty-like pressure-sensitive adhesive, commonly used to attach papers to walls or other surfaces. The original version of the product was blue, but many colours are now available. Blu-Tack can leave an oily stain on paper materials if attached for a long period of time. In the USA, a similar, competing product in an orange colour is marketed under the brand "Elmer's Tack.'