Villain is 88/23/2 and is an absolute maniac - raising and betting with air and stacking off with them too. How do I approach this?

$0.25/$0.5 Pot Limit Holdem
6 players
Converted at

Stacks:
UTG ($85.55)
UTG+1 ($68.50)
Hero ($50.00)
BTN ($47.50)
SB ($50.00)
BB ($107.65)

Pre-flop: ($0.75, 6 players) Hero is CO [As]
UTG calls $0.5, UTG+1 calls $0.5, Hero raises to $2.75, 3 folds, UTG folds, UTG+1 calls $2.25

Flop: [Jd][4d] ($6.75, 2 players)
UTG+1 checks, Hero checks

Turn: ($6.75, 2 players)
UTG+1 bets $6.75, Hero calls $6.75

River: ($20.25, 2 players)
UTG+1 bets $20.25, Hero calls $20.25

Final Pot: $60.75

I would only call turn if i planned on calling most rivers.
If I got an A or a K river like you did I definitely would be shoving over the top.