If you search online for World's Largest Gummi Bear, you get a link to Vat19.com offering a measly 1/2 lb gummi and their 'World's Largest' at 5 lbs. They also claim "there is no candy more magnificent or more powerful". Well unfortunately for them I made an even bigger gummi sculpture (at 6lbs though not a bear) 7 years ago!
Gummi=Gummy. Haribo calls them Gold Bears. Black forest calls them Gummy Bears. Whichever you prefer. Original German was gummibär, so that probably originated the gummi bears.
I did this experiment in my youth. So don't blame the current me for the brash and questionable nature of this idea. You've been warned!
Step 1: Procure Gummis and cake mold
The cheapest 5lb or 6lb bag was from Brach's at 6lbs for $11.50.
The lowest $/lb ratio for gummi bears was from Albanese at $1.70/lb (10lb for $17) :
And going for only top quality from Haribo reveals this gem of a deal 12 lbs for $34.
This should provide plenty. For the Brach's there were 5 colors and for the Haribo and Albanese there appear to many more. So if you want a solid colored gummi monster look for places where you can either buy a bunch of one color or you'll have to buy many many pounds of this stuff.
How I came into 6 lbs of gummi bears was a funny story. After finding they sold such a delightful item at costco, I off-handedly mentioned they should be the token prize at a prize raffle for our highschool band end-of-the-year party. Because of my fortunate luck, I actually won said raffle.
Be creative when choosing a mold. I just got a cheap cake mold from the 99¢ store or something like that. I wanted to do both sides, but it turns out that would've required twice as much and I didn't want liquid gummi seeping through the seems of the mold.