Bash find unpack

find . -maxdepth 1 -type f -regex "^.*\(png\|gif\)$" -exec rm {} \;

find                      = Linux find command.
.                         = current directory.
-maxdepth 1               = Depth in folders beyond this one. 1 = /only/ this current folder.
-type f                   = Regular file. -type d = directory.
-regex "^.*\(png\|gif\)$" = "any file ending in PNG or GIF"
-exec rm {}               = Delete this file, represented as {}, by executing the Linux remove command.
\;                        = Terminate the "-exec rm"

"Search in this directory for any regular, non-directory file whose name ends with 'gif' or 'png' and delete it."