The Variable Cracker (Hamadryas feronia) is quite a large butterfly. Its wingspan is 73–83 mm.
The Variable Cracker is often seen basking on tree trunks, adopting a head-downward posture, with the wings flattened against the bark.
Males bask in this position for long periods to await potential mates.
Males can make a cracking sound (the crackling of bacon in a frying pan) when they dart out at passing insects (and people). 
Only males can produce this sound which may possibly deter competing males from occupying the same territory, or could act as a trigger to initiate the response from a female during courtship.
Hamadryas feronia is easily confused with Hamadryas februa, but the latter has red crescents within the ocelli on the hindwings.
There are two subspecies.
This is Hamadryas feronia farinulenta which is found in Mexico, Guatemala, Honduras, Venezuela, Colombia and Trinidad.

Sumidero Canyon National Park, Chiapas, Mexico, 20 April 2011