Fizzy Ducks, advertised as “Blackpool’s biggest and best gift shop”, is flogging the sweet treat for £3 a tub.
The item - branded “from Colombia with love” - is not made from cannabis but ingredients include sugar, artificial flavouring and E-numbers to turn it green.
Dad Mark Rackham, who was shopping with his two young daughters aged nine and 10 at Blackpool’s North Pier, Lancs, said: “F*g scandalous in my opinion.
"Blatantly targeting kids and getting them interested in drugs - that is pretty low.”
The shop - right on the promenade and close to Blackpool Tower - also sells cannabis flavoured sweets called “Ganja Rock”.
Chris Nutter, 30, said: “It’s a daft idea. Anything that encourages kids to think drugs are harmless is a mistake and shouldn’t be sold.”
Linda Matthews, 52, said: “I don’t think it’s sensible to be selling it whether it’s just a gimmick or not.
“Blackpool already has a problem with drink and drugs, so I do not think youngsters need any encouragement.”
Louisa Kay, 39, said: “I don’t think for one minute there is any cannabis in it but it does put temptation into youngsters’ heads.
“If they think it’s harmless, they may try a joint and go on to harder drugs from there.”
A store spokeswoman declined to comment.