Opuntia vulgaris is a hardy form of the Prickly Pear, though it won't handle frosts and should be brought indoors over winter if there is a danger of frost.
These are very decorative succulents from South America that are best grown away from people areas due to the unpleasant spines.
But they do make up for it with their wonderful bright yellow flowers, tinged with red that grow along the plant edges during summer and on into autumn, making a splendid display.
Can be grown in pots indoors, but again, taking care to avoid brushing past them.