Donkey -- the symbol of the Democratic party. According to "The Political Arena", the donkey was first used to represent the Democratic party in a political cartoon in 1837.
Elephant -- the symbol of the Republican party. "The Political Arena" says elephant was connected with the Republican party in cartoons as early as 1860. An 1874 cartoon in Harper's Weekly was the important factor in sticking the elephant as the Republican symbol.
Blue Dog -- Blue Dog Democrats claim to be moderate-to-conservative Democrats who are committed to financial and national security. I think they are supposed to be former "yellow dog" Democrats who claimed they had been "choked blue" by their own party.
Rino -- these critters charging the savanna go by their acronym RINO (Republican In Name Only). In general these are Republican politicians whose voting records are contrary to the party platform. Specifically in Texas they are Democrats who saw the handwriting on the wall -- the Republican takeover of state politics -- and jumped ship for political expediency. Chuck Hopson, House District 11, is one such example. Virtually assured he could not be re-elected as a Democrat, he is now a RINO. Those Republicans who support his re-election in opposition to the local grass root Republicans of HD 11 are suspect as well (including Gov. Rick Perry, Lt. Gov. David Dewhurst, Sen. Kay Bailout Hutchison, Sen. John Cornyn, Agricultural Ommissioner Todd Staples, State Sen. Kevin Eltife, Rep. Joe Strauss)
It's a dog eat dog world out there (and Elephants and Rinos and Donkeys). Tomorrow's primary will tell who survives.