Goodness, I found a shiny Hawlucha, 3 shiny Weedle and a shiny Alpha Kakuna within the span of 2 minutes

All three of the Weedle and the Kakuna were all in one area, near that area with the Dratini and 4 Bellsprout on the roof. They must have spawned in during all the times I was bench-resetting for a shiny Dratini and I didn't notice.