Male genitalia!
One of the guys was asking about this last night in PS2.
Rather than judge which ones are funny I’ll just list the most common terms and then any others I’ve heard.
Probably important to know that unless you’re using a common word it’s more typical to implement a euphemism or make up your own metaphor if you’re going for laughs:
Cock, dick, penis, willy
Shaft, schlong, rod, stick, Johnson, little guy, Choad, joystick, junk, one eyed trouser snake, babies arm holding an apple, wiener, knob, prick, babymaker, fuckstick, bishop, chub, pork trumpet, pink oboe, dingaling, schwanz, micropenis, wang, todger, boner, bellend, tool… *
- will add if I remember more