What are these teardrop shaped thingamabobs on the bottom of the Panavia Tornado?
They appear to be related to changing the oil.

The Tornado's flight manual is available online. Page 448 shows what seem to be the features you're talking about:



The features are the ones marked as "12." The previous page has a legend describing them simply as "engine oil."

This probably also explains why they're not placed symmetrically. It seems the engine oil access is off to the side, so each teardrop is a bit to the right of the engine's center line (that's most visible in the second picture).