This Seeking Tech guide will explain how you can jump on the trunk of the Safari Park elephant building.
Use the following video as a reference:
If you haven’t done so already, make sure you unlock the Safari Park on the Crash Site hub.
Next, you need to jump to the Gatcha Lab building from the small hill behind it.
You can then jump to the Safari Park building.
You then need to tiptoe towards the trunk until it props up.
Afterwards, carefully jump on the trunk. Try not to jump too far ahead or it will retract.