A couple of years ago I can remember people in my class getting things like 'lifeguard' and the ubiquitous 'undertaker', but i think i hold the claim to the best career ever suggested.
Scientific Glass Blower. Honestly.

Changing room game. When a small child (victim) bends down to put his socks on, a boy tall, hard, and shameless enough pins the victim's face to the wall by reversing his arse onto it at fearsome speed. The victim's natural reaction will be to either avoid cracking his head on the wall (a softer but more disgusting fate) or to avoid the approaching arsehole (possibly resulting in concussion). For best results, the victim's nose may actually enter the anus.

An alternative used at my primary school was "were you born in happiness or symphony?". Nerdy spack boys (like myself) would usually say symphony, thinking it was cleverer, only to be told "eurrr! you were born with a sim-fanny!"

Futuristic suffix, essential in games involving robots or Daleks.
Usage: put on a metallic voice and declare "I. AM. ALANATRON. EX. TER. MIN. ATE." A warning to people whose names rhymed with Tron, though. "I. AM. JOHN. TRON." makes you sound like a bit of a gaybot, marks you out as a target for ex. sperm. in. ation.
Tron making regular objects sound futuristic and robotic, it's arguable that William's arcade game Robotron 2024 was gilding the lily a touch.

Abusive chant directed at me by class bullies for daring to wear an iron on "Fighting Fantasy" transfer on my jumper. The chanting started in a normal voice, but was gradually replaced by a mock-spastic voice and finally stopped altogether when one of my tormentors decided it would in fact be a better idea to spit on me.

The victim would be clamped to the ground and force fed grass. Meanwhile, the perpetrator and any invested observers would remind the victim how fortunate he was by singing the words to the Anchor Butter song: 'we are lucky cows - we chew the cud and browse'.

Count yourself lucky. There are some cows out there who aren't chewing the cud and, erm, browsing. You wouldn't want to be one of those cows, would you?

Similarly, a great word, and very similar to spasmojesticles. A superb slant on spazmo and testicles, with a bonus "j", which is the funniest letter.

"You pogglesnatch!" was the anguished wail of Bill Murchison whenever he was wronged.
Other scathing put-downs that he came out with were 'grankboggle', 'bogglewonk' and his finest hour - 'you saxophonist'.
(A brief googling shows that this website is the only one in the world to contain the words grankboggle or bogglewonk. What a coup! - Log)

pinfinger puppet shows
Puppets are made by making stick people out of safety pins, and attaching their arms to the index and thumb of your right hand, and the legs to the index and thumb of the left. More effective when a few people get into the act. Also works with paper clips.
(How? How does this work? Any photographs of this haunting pinfinger puppet show will be placed immediately on the front page. If Phil says it can. - Log

My Aunt Nellie had a hole in her belly
And a hole in the biscuit tin
She was sitting on the grass
With her finger up her arse
And her tits going ding-a-ling-a-ling.

If anybody has any theories as to where the biscuit tin fits in to all this, I'd love to know.