Ricky is a compulsive liar with a Psycho addiction. He has a Vault 22 jumpsuit and a Pip-Boy 3000 which he got from a dead prospector that came from Zion. The symbol of good loot is why he's returning with the Happy Trails' expedition. Ricky says he grew up near Dayglow, stating one of his useful skills to be "a third nut that glows in the dark" because of his high exposure to radiation in his youth.
Happy Trails Expedition: Ricky accompanies the caravan to Zion Canyon. If he is not convinced to leave the group, he will admit in a panic that his Pip-Boy doesn't even work during the ambush (the screen is locked up but the button to reset the device is missing), shortly before he is killed. As with all the members of the ill-fated Happy Trails expedition, Ricky's death is a scripted event and cannot be avoided.
Before leaving for Zion, the player can call Ricky out on all his lies when the appropriate checks come up in conversation. Then, after all of Ricky's dialogue checks are used up, the player can tell Ricky he's not cut out for the expedition or either tell on Ricky to Jed Masterson or blackmail Ricky into carrying some of the player's gear, thereby extending the player's weight limit for traveling with the Happy Trails Expedition to 100 WG.
With a medicine check the player can see that he's a Psycho addict and can push it further by asking if he brought enough Psycho to last the trip. The player can then sell Ricky some Psycho or Fixer for 30 caps per Pycho, up to 10 hits, and 80 caps for a Fixer. If this check is done at the very start of the add-on, it is another way to convince Ricky to ditch the trip in case of a withdrawal in the middle of the trip.
He tells the player that he killed a BoS Paladin by firing through the eye slit by using an 11mm submachine gun, which is a lie. The player can respond that the eye slit is bullet-proof if the player has Power Armor Training, or there is no such thing as an 11mm submachine gun with a Guns skill of 45.
He claims that he has encountered "Deathjaws". With a Survival skill of 20, the player can correct him and ask him if he meant deathclaws. He will say no, and assert that Deathjaws are similar to deathclaws, but with bigger teeth.
When Ricky comments about his "third nut" to a female player and offers sex on the expedition, you can use Black Widow and say that you will remember to bring tweezers and a microscope. If possessing a high enough Guns skill, the player can say it'll make it easier to shoot them in the dark.
Ricky also comments on getting his Vault 22 jumpsuit from Vault 22, and that he has to follow his "vow of secrecy". You can call him out on the lie if you have been to Vault 22 and say that it has been abandoned for some time, or with a Perception of 6.