My wizard used summon monster VI to summon a red slaad for a battle. One of a slaad’s attacks is implanting eggs in its victims, which is apparently how slaadi reproduce. Will the eggs disappear when the spell expires and the slaad departs, or do they remain?
Any magical effect a summoned creature creates ends when the summoning ends (even if it is normally permanent). Many such effects, however, actually have instantaneous durations, but lasting consequences. Energy drain, for example, is instantaneous, though the victim may feel the loss for a long time.
Anything separated from a summoned creature’s body also vanishes when the summoning ends. This includes parts severed from the body and anything produced from the creature’s body, such as poison or eggs. In the case of poison, any effects the venom already has caused remain. For example, a summoned fiendish viper bites and poisons a character, who takes 3 points of temporary Constitution damage. If the summoning ends before the poison’s onset time expires, the poisoned character takes no additional effects from the poison, but the 3 points of temporary Constitution damage remain.