The relationship between the rival vampires will soften in the HBO drama's fifth season, Skarsgård told E! Online.
"There's a bit of a bromance going on this year between [my character] Eric and Bill (Stephen Moyer)," said the Swedish actor.
"It's fun because I love Stephen Moyer to death and after four years of butting heads, this is more like Butch Cassidy and the Sundance Kid. We have a common enemy and we have to team up this year."
Lucy Griffiths will join True Blood next season as Eric's sister Nora. The actress recently revealed that the two siblings have "a fiery love/hate relationship".
True Blood returns to HBO on June 10 in the US. In the UK, the fifth season will air on FX in the autumn.