Dragoness’ Cornfields area has a nice “easter” egg: If you kill a little boy from the area, there is a small chance that the little boy’s big brother pops up.

In the past, when the little boy had valuable loot, the big brother was quite typical newbie trap:

log-2002-02-07.txt.bz2:Little boy's big brother shouts 'I butchered Darkwell for breakfast, who's up for dinner?'
log-2002-02-07.txt.bz2:Little boy's big brother shouts 'I hope you have a life insurance, Moonglaze!'         
log-2002-02-07.txt.bz2:Little boy's big brother shouts 'Gee, sorry about that Adler *snicker*!'
log-2002-06-07.txt.bz2:Little boy's big brother shouts 'Barrabas was just DOGMEAT, who is next?'
log-2002-06-07.txt.bz2:Little boy's big brother shouts 'My HAMSTER fights better than you do, Veldrin!'
log-2002-06-07.txt.bz2:Little boy's big brother shouts 'Barrabas should learn to use consider!'
log-2002-06-07.txt.bz2:Little boy's big brother shouts 'Creal no longer causes lag!'
log-2002-06-07.txt.bz2:Little boy's big brother shouts 'Rald no longer causes lag!'
log-2002-06-07.txt.bz2:Little boy's big brother shouts 'Goldie isn't much of a party animal!'
log-2002-06-07.txt.bz2:Little boy's big brother shouts 'My HAMSTER fights better than you do, Belfarath!'
log-2002-06-07.txt.bz2:Little boy's big brother shouts 'Ukemi dies from a single blow, well almost at least!'
log-2002-06-09.txt.bz2:Little boy's big brother shouts 'Oxes barely scratched me before dying!'
log-2002-06-09.txt.bz2:Little boy's big brother shouts 'Victor isn't much of a party animal!'
log-2002-06-09.txt.bz2:Little boy's big brother shouts 'Locray is a LOSER!'
log-2002-06-09.txt.bz2:Little boy's big brother shouts 'Dracian just made my day!'
log-2002-06-09.txt.bz2:Little boy's big brother shouts 'Decapit barely scratched me before dying!'
log-2002-06-09.txt.bz2:Little boy's big brother shouts 'Culain should stick to PIGEONS! I want a tougher challenge!'
log-2002-06-09.txt.bz2:Little boy's big brother shouts 'Let's do that again sometime, Dalah!'
log-2002-06-09.txt.bz2:Little boy's big brother shouts 'Susan isn't much of a party animal!'
log-2002-06-09.txt.bz2:Little boy's big brother shouts 'Gee, sorry about that Nips *snicker*!'
log-2002-06-09.txt.bz2:Little boy's big brother shouts 'Locray is a LOSER!'
log-2002-06-09.txt.bz2:Little boy's big brother shouts 'Poe is in a much warmer place now!'
log-2002-06-12.txt.bz2:Little boy's big brother shouts 'Nips bites the dust!'
log-2002-06-12.txt.bz2:Little boy's big brother shouts 'Peijooni died like a DOG!'
log-2002-06-12.txt.bz2:Little boy's big brother shouts 'Time to meet your maker, Tybert!'
log-2002-06-12.txt.bz2:Little boy's big brother shouts 'Next time, Locray, bring me your friends too!'
log-2002-06-12.txt.bz2:Little boy's big brother shouts 'Vippy is in a much warmer place now!'

In some of the general tunes, the loot from the little boy got downtuned and it makes no longer sense to kill him, so the big brother is rarely present.

However, I got lucky and managed to summon the big brother:

k boy
********************** Round 1 **********************
You grab Little boy.
You tumble Little boy's dodge.
You foot-sweep Little boy.
Your superb dexterity avoids a nasty ambush.
A big barbarian arrives and yells 'Don't you dare to hurt my little brother!'
You miss.
You grab Little boy.
Little boy gets an acute case of iron-poisoning.
Little boy is DEAD, R.I.P.
...
Hp:1250/1250 Sp:104/511 Ep:444/568 Money:3830+859833 28 kgs Exp:30881 Eq:monkbattle C:392,73|11:19|
l
Forest path.
This path goes through the forest. There is a big old birch here. The path
leads from north to the east. There are several sets of footprints on it.
Above you is a chilly, rolling, heavily clouded night sky. You have to brace
yourself against the strong wind. The moon is not visible.
Obvious exits are: n and e.
The pumpkin helmet
a pile of zinc coins
20 bronze coins
a huge barbarian warrior hunting down you
a blue-glowing soul companion [Thelo]
Hp:1250/1250 Sp:104/511 Ep:444/568 Money:3930+859833 28 kgs Exp:30881 Eq:monkbattle C:392,73|11:19|

The big brother was slightly physres and it took me 5 runs to kill him. I also died once when he was blocking me from running away:

The barbarian yells 'I am not done with you yet!' and kicks you into stomach, effectively
stopping your escape attempt!
You are stunned and unable to do anything.