Carrot

The term "Carrot" is used as slang to refer to a needle, specifically because of the orange color of the needle's tip.

Since Carrots have an orange color, And the needle used to inject the drug also has an orange tip
drug users slang refer to the needle as a "Carrot" based on the visual similarity and color

Roadhouse: I'm ready to shoot some dope.
Timah: Let me grab a Carrot