Guild Wars 2

You can sometimes do that with reflection – if a projectile spawns a creature when it lands, and you reflect it, the creature spawns as an ally not an enemy. Some risen spiders throw out eggs after they die, so maybe you reflected one of those?

I am pretty sure that is what happened (you reflected one of the eggs). I am also fairly sure that it’s working as intended. You can also reflect things like mordrem troll insect swarms etc. It’s fun